Welcome to ChartedSails' Sailing Data Analysis Course! We're delighted to have you join our community of data-driven sailors. This course will help you learn how to track, analyze, and improve your sailing performance through powerful data visualization and insights.



Welcome to ChartedSails' Sailing Data Analysis Course! We're delighted to have you join our community of data-driven sailors. This course will help you learn how to track, analyze, and improve your sailing performance through powerful data visualization and insights.

## What You'll Learn

Throughout this course, we'll cover:
- [How to capture your sailing data](/sailing-data-course/capturing-data) with various devices
- [Preparing your data](/sailing-data-course/preparing-data) in the most effective way
- [Tools to use in your data analysis](/sailing-data-course/tools-of-the-trade) and the measurements that drive speed
- Analyzing races with [proper setup](/sailing-data-course/race-setup) and [data visualization](/sailing-data-course/race-analysis)
- [Sharing insights](/sailing-data-course/sharing-insights) with your crew and team
- [Using video](/sailing-data-course/improving-with-video) to improve technique
- [Organizing effective debriefs](/sailing-data-course/group-debriefs) for groups


## Who This Course Is For

This course is designed for:

- Competitive sailors looking to gain an edge in races
- Coaches who want to provide data-driven feedback to their teams
- Recreational sailors interested in improving their skills
- Anyone curious about the intersection of sailing and data analysis

No prior experience with data analysis is required, though basic sailing knowledge is assumed.

## Getting Started

If you haven't already created an account, you can sign up at [chartedsails.com](https://chartedsails.com). All the techniques in this course will be demonstrated using the ChartedSails platform.

ChartedSails allows you one free upload per month. It's a great way to learn the tool and see the benefits of data analysis in your sailing. If you need more uploads, you can upgrade to a paid plan at any time.

## How to Use This Course

Each section builds on the previous one, so we recommend working through them in order. However, if you're already familiar with certain aspects, feel free to jump to the sections most relevant to you.

Throughout the course, you'll find:
- **Step-by-step guides** for using ChartedSails features
- **Pro tips** from experienced sailors and coaches
- **Visual examples** to illustrate key concepts
- **Action steps** to help you implement what you've learned

---

Ready to start your journey toward faster, more data-driven sailing? Let's begin with [capturing your sailing activities](/sailing-data-course/capturing-data).


Welcome to the Sailing Data Analysis Course

> "You can't improve what you cannot measure"

What is the difference between COG and Heading?

What is the best way to record a group of boats?



> "You can't improve what you cannot measure"

If you want to sail faster, you need to start by capturing your performance data. It's a simple habit to build, and the most common regret we hear from sailors is: "I wish I had recorded my first year with the boat." So start today—and don't skip a session!

## Dedicated Sailing GPS Devices

Most sailors choose to record their activities with a dedicated sailing GPS. These devices are purpose-built for the marine environment and provide the most accurate data.

### Velocitek Prostart

<img src="/assets/img/velocitek-prostart.webp" alt="Velocitek Prostart" class="img-fluid" style="max-width: min(100%, 400px);"/>

- **Pros**: Excellent for starts, large screen, easy to use, and great for all types of sailing.
- **How to use with ChartedSails**: Your data is automatically recorded every time you sail. Just plug the Velocitek into your computer and you will find a VTK file that you can upload to ChartedSails.
- **Recorded data**: GPS position, speed, course, heeling and pitch angle, heading.
- Pings of the marks and start timer are also recorded.

### Vakaros Atlas 2 / Atlas Edge / Atlas

<img src="/assets/img/vakaros-atlas.webp" alt="Vakaros Atlas 2" class="img-fluid" style="max-width: min(100%, 400px);"/>

- **Pros**: High precision, easy sync, and great for all types of sailing.
- **How to use with ChartedSails**: Your data is automatically recorded every time you sail. Just use the Vakaros mobile app to export your data. You will get a VKX file that you can upload to ChartedSails.
- **Recorded data**: GPS positions, speed, course, heeling angle, pitch angle, heading.
- Pings of the marks and start timer are also recorded. If you are participating in a RaceSense event, you will receive wirelessly the position of the starting line and the race timer. These will be recorded too.
- With a wind sensor, apparent wind speed and direction are recorded.
- With a boat speed sensor, boat speed, water temperature and water depth are recorded.
- With a Calypso load sensor, you can record the load on your rig.

- **Important**: If your Atlas is not mounted in a fixed position, make sure to turn off the "Fixed Mount" option in the settings. Otherwise, the heading angle, heeling angle and pitch angle will be incorrect.

### Sailmon Max

ChartedSails is compatible with the Sailmon devices. As of March 2025, Sailmon announced that they were acquired by Vakaros. It's not clear yet how long the Sailmon devices will be offered for sale but ChartedSails will continue to support them.

- **Recorded data**: GPS position, speed, course, heeling and pitch angle, heading.
- Unfortunately, Sailmon Max does not save the pings of the marks in the data file.

## Smartwatches
Many sailors use smartwatches like Garmin for convenience. With automatic synchronization, you just need to link your Garmin account to ChartedSails, and you'll never miss capturing your data!

[**Read our Garmin Guide →**](/blog/take-your-garmin-watch-sailing)

## Smartphone Apps
Don't own a dedicated GPS? No problem! You can use a mobile app on your phone to record data.

For iOS users we recommend `Open GPX Tracker`. It is free, no ads and lets
you easily export GPX files that are compatible with ChartedSails. For higher
accuracy, set the "Activity Type" to Fitness in the settings.

[![Open GPX Tracker for iOS](/assets/blog/record-howto/opengpx-tracker.png)](https://apps.apple.com/us/app/open-gpx-tracker/id984503772)
_Click the image to download OpenGPX Tracker for iOS._

For Android users, we recommend `GPS Logger`. It is also free, without ads
and offers easy export of GPX files.

[![GPS Logger](/assets/blog/record-howto/gpslogger.png)](https://play.google.com/store/apps/details?id=eu.basicairdata.graziano.gpslogger)
_Click the image to download GPX Logger for Android._

For both iOS and Android users, the easiest way to collect the files is to
email them to yourself. A slightly more advanced option is to save them to a
cloud disk storage like Dropbox, Google Drive or iCloud.

## Common Questions

### What data should I record?

Most devices will automatically capture your GPS positions over time (your track), your Speed over ground (SOG), and your Course over ground (COG).

Dedicated sailing GPS devices will also capture additional data such as heeling angle, pitch angle and heading. And when connected to additional sensors, they may be able to also capture wind speed and direction, boat speed, water depth and temperature, and more!

In general, if your GPS device can capture it, you will be able to see it in ChartedSails. If something is missing, let us know!

### What about recording races?

Sailing GPS devices will also capture your pings of the marks and the time of the start timer. This makes it much easier to find the race in your track. ChartedSails will also load and display this information.

### Recording frequency?

The recording frequency controls how many points per seconds are saved by your GPS. In general, the higher the frequency, the more accurate the data, but the more battery it will consume.

For traditional sailing, a frequency of 1Hz is usually sufficient but we would still recommend 5Hz to have smoother tracks and a better experience.

For foiling and other fast boats, 5Hz is a minimum.

### What is the difference between COG and Heading?

COG (Course Over Ground) is the direction in which the boat is moving over the ground, while Heading is the direction in which the boat is pointing. The difference between the two can be significant, especially when sailing upwind or downwind.

To capture heading, you need a device that has a compass. Most dedicated sailing GPS devices will have this feature, but not all smartwatches or phone apps will.

### Which file format should I use?

ChartedSails supports the most common file formats: GPX, CSV, TCX, FIT, and NMEA. We have inspected many files by hand so that we can load them properly, use the right units and make the best use of the data available.

If the files exported by your GPS are not recognized by ChartedSails, please contact us. We will do our best to support your device.

**Velocitek and Vakaros both offer a special format (respectively VTK and VKX). These formats are the most complete and the only way to get the best experience in ChartedSails.**

### What is the best way to record a group of boats?

For clinics, sailing camps and regattas, there are a few different options. Read our dedicated [Group Debriefs Guide](/sailing-data-course/group-debriefs) for more information, and please do contact us for the best solution for your event.


## Your Next Steps

1. **Choose your recording method** from the options above
2. **Set up your device** on your boat and make sure you are familiar with operations (recommend testing everything on a walk or bike ride!)
3. **Test it out** on your next sail

Once you've selected and set up your recording method, you're ready to move on to [making the most of your data](/sailing-data-course/preparing-data) with effective note-taking techniques.


Capturing Your Sailing Activities

Before you can analyze your data, we need to do a little bit of preparation and organization. ChartedSails makes this easy and intuitive.



Before you can analyze your data, we need to do a little bit of preparation and organization. ChartedSails makes this easy and intuitive.

## Collecting Files

Most methods of data capture will provide you with a file. If you are capturing data for multiple boats and multiple days, you will quickly end up with a lot of files. To make the most of your data, you need to organize it effectively.

If you are only capturing data for one or two boats, this will not be a problem.

For bigger groups, a practical advice here, is to create a folder for each event and store all the files (for each day and each boat) in it. We recommend including the date, sail number and name of the boat in the filename. It will make things easier for you later.

Once uploaded in ChartedSails, your data will be organized by boat and by date, and you will not need to worry about this anymore.

## Upload Your Data

To start exploiting your data, you will need to upload it to ChartedSails. The process is extremely easy and intuitive. Just click the "UPLOAD" button on your dashboard and drag and drop your file into the upload area. ChartedSails will automatically detect the file type and start processing it.

![Uploading a file to ChartedSails](/assets/sailing-data-course/upload.png)

After processing, ChartedSails will ask you to provide some information such as the name of the boat. If it's the first time you upload data for this boat, the program will also ask you to provide the boat type and the sail number. The boat type is important to properly represent the length of the boat and will also be used for some racing analysis.

![Add boat](/assets/sailing-data-course/add-boat.png)

If your boat class does not already exist, you can quickly add it.

## Add more boats

After uploading your file, ChartedSails will show the sailing activity on the map.

If you were not sailing alone, there are two ways to add more boats to your activity.

### When you have all the files

If you already have the files for the other boats, you can add them with the "ADD BOAT" button and repeat the upload process.

### When you do not have the files

If you sailed with someone that did not share their data, you can invite them to join the activity and add their data.

Click the "SHARE" button and send them an invitation to join your session. They will get an invite by email and will upload their tracks by themselves. Both of you will see both boats.

![Share session](/assets/sailing-data-course/share-session.png)

You can repeat this process as many times as needed.

## Provide wind direction

Sailing insights will obviously depend heavily on the wind direction. ChartedSails requires that you give a general wind orientation before most of the tools become available.

To set the wind direction, use the rotating compass in the top right of the screen and rotate the map until the wind is coming from the top.

![Set the wind](/assets/sailing-data-course/help-setwind.gif)

## Trim your session

It regularly happens that we keep the GPS recording on the freeway back home and this makes for some disturbing maximum speed.

You can easily trim-off data before and after sailing with the "EDIT" button.

![Trim session](/assets/sailing-data-course/trim-session.gif)

We recommend keeping the entire day of sailing. From leaving the dock until you return to the dock. We will discuss later how to highlight specific races in the day.


## Tips to Make the Most of Your Data

 Your GPS will capture most of the technical information, but we've learned that a few simple notes during your sailing day will make a huge difference in transforming that data into real improvements.

### 5 Key Things to Record During Your Sail

Even the best GPS can't capture everything. Here are the critical details to note during your sailing session:

1. **Crew Information**
   Who was on board? Different crew weights and skills affect performance.

2. **Sail Configuration**
   Which sails did you use? Note any changes made during the session.

3. **Weather Conditions**
   Record wind speed/direction and wave conditions, including any changes throughout the day.

4. **Start Times**
   Modern sailing GPS devices often capture this automatically, but if yours doesn't, write down the exact time of all starts.

5. **Experiment Details**
   Working on improving jibes? Trying different heel angles? Note the time and nature of any technique experiments you try.

### How to Capture These Notes

You don't need a complicated system:
- Use a small waterproof notebook
- Take quick voice memos on your phone
- Snap photos of the crew, whiteboard and sails with your phone


Here's what effective notes might look like:
```
April 12 - Team: Alex, Maria, Thomas
- 12:30-1:00: Light wind 8-10kts, flat water, tested new jib trimming technique
- 1:15: Wind shifted +15°, increased to 12-14kts
- 1:30-2:45: Five practice starts, working on acceleration
- 2:50-3:30: Three races, using higher pointing angle upwind
```

### Adding Your Notes to ChartedSails

When you first open your session in ChartedSails, add your notes:
- In the session title (e.g., "J/70 Training - 15-18kts - New jib")

- Using the notes feature on the timeline
![Add notes to the timeline](/assets/sailing-data-course/add-note.gif)

- Create highlights on the timeline to quickly find interesting moments

![Create a named selection](/assets/sailing-data-course/create-named-selection.gif)


## Action Step

Before your next sailing session, create a simple template for your notes. Having a structure makes it easier to jot down the important details quickly.

Now that you've learned how to enhance your raw data with effective notes, you're ready to move on to [understanding key performance indicators](/sailing-data-course/tools-of-the-trade) that will help you sail faster.


Preparing Your Sailing Data

2. Straight Line Speed: Understanding VMG

3. Maneuver Efficiency: Measuring Acceleration



Now that we have uploaded our data to ChartedSails, added all the files and
notes in our possession, it's time to learn what are the different types of
measurements we can take, and how to do it effectively.

We will start by discussing the tools available in the interface to take
measurements and then discuss interesting measurements.

## The Instrument Panel

In the left part of the screen, you will find the Instruments panel. This panel displays all the data available for all the boats at a given point in time indicated at the top.


![The instrument panel](/assets/sailing-data-course/instruments.png)

You can resize this panel to make it wider and show more information:

![Resize the instrument panel to show more information](/assets/sailing-data-course/resize-instrument.gif)


## The Performance Panel

The Performance Panel is the second tab in the same window. Where the instruments always show data at one point in time, the performance panel shows **aggregated data**.

Aggregation is a data analysis term that simply means that we are grouping many points together and summarizing them into one or a few values. The simplest example of aggregation, and perhaps most often used in sailing is the **Average**. Another one that you are familiar with is the **Maximum**.

A key aspect of aggregation is understanding what data points have been summarized. ChartedSails always makes this clear by showing at the top of the panel the points that have been included.

By default, ChartedSails aggregates over the entire day so you can see what distance you sailed, what was the average speed, max speed, etc.

![Performance panel](/assets/sailing-data-course/performance.png)

You can very easily zoom on a specific time period by clicking on the timeline and dragging the mouse. When you do this, the Performance panel updates to show you data for just the interval you selected. Notice also that the time at the top changes to show the selected interval.

![Make a selection](/assets/sailing-data-course/selection.gif)
![Observe the performance panel](/assets/sailing-data-course/selection-performance.gif)

ChartedSails can do even more complex aggregation for you. In the next chapters, we will discuss how to compare the performance of different boats in one race or one leg of a race, even when they started and finished at different times.

## The graph

At the bottom of the screen ChartedSails represents the data visually. By default the Speed Over Ground is represented.

To see other variables, you must first select a specific boat and then select which variable to look at:

![Use the graph](/assets/sailing-data-course/graph-variables.gif)

## Boat tails

Another essential tool is the tail selector. It controls how much of the track is represented on the map and lets you visually represent the speed by coloring the track.

In Tail mode, ChartedSails will only show the last 10 minutes in a fading color that is unique to each boat.

In Full Tail mode, ChartedSails represents the entire track of the boat.

In Speed mode, ChartedSails represents the Speed Over Ground. The scale is specific to the current selection.

![Tail selector](/assets/sailing-data-course/tail-selector.gif)

## Quick Measurement

The last tool we will discuss is the quick measurement tool. This allows you to very easily take measurement over any straight line segment. It makes it trivial to compare angles and speeds of tacks or multiple boats.

![Quick measurement](/assets/sailing-data-course/quick-measurement.gif)




## Three Areas to Focus On

### 1. Practice Volume: Quantity Matters

To get results, you need time on the water. ChartedSails automatically tracks:

- Total sailing time
- Number of tacks executed
- Number of jibes completed
- Distance sailed

**Action Step:** Build a profile of what a regular training day looks like for you, then set a goal to increase your numbers by 10-15% next time.

### 2. Straight Line Speed: Understanding VMG

Velocity Made Good (VMG) is the speed component directly toward your destination, whether sailing upwind or downwind. It's your most important performance metric.

ChartedSails makes it easy to analyze your VMG performance:

1. Hover your mouse over the chart to see SOG (Speed Over Ground), VMG, and TWA (True Wind Angle) for each tack
2. Look for patterns in your data to answer these questions:

   - When is your VMG the highest?
   - What boat speed and angle produce your best VMG?
   - Do you tend to pinch (sail too high) or foot (sail too low)?
   - What heel angle gives you the best performance?

**Action Step:** Identify your optimal TWA for maximum VMG in different wind conditions and make note of it for future reference.

### 3. Maneuver Efficiency: Measuring Acceleration

Every tack or jibe costs you energy and speed. The key questions are:
- How much speed did you lose during the maneuver?
- How long did it take to regain your speed?

To analyze this in ChartedSails:

1. Turn on the Speed-colored track mode
2. Highlight maneuvers on the timeline
3. Look for the color changes that indicate speed loss and recovery

**Action Step:** Compare your fastest maneuvers with your slowest ones. What techniques are you using differently?

## Practical Example: VMG Optimization

Here's what VMG analysis might reveal:

```
Wind: 12-14 knots
Best VMG Upwind: 5.2 knots
- Achieved at 42° TWA
- Boat speed: 6.4 knots
- Heel angle: 18°

Common mistake: Pinching at 38° with only 4.7 VMG
```

This simple insight could gain you 0.5 knots VMG - potentially minutes over a long upwind leg!

## One design coaching techniques

For more inspiration, continue on to [our interview of "Fuzz" (Grant Spanhake)](/blog/one-design-basics) on the blog. He goes into details on what he likes to focus on when coaching one-design groups.

## Pro Tip

Create a "speed journal" where you record your optimal angles and speeds in different conditions. Over time, this becomes your personal polars for your boat.

Now that you understand the key performance indicators, you're ready to move on to [analyzing your races](/sailing-data-course/race-setup) to extract even more valuable insights.


Tools of the trade

We train so we can win more races. Race analysis is a powerful feature in ChartedSails, and we've worked hard to make it intuitive and insightful.

Step 1: Highlight the Race on the Timeline



We train so we can win more races. Race analysis is a powerful feature in ChartedSails, and we've worked hard to make it intuitive and insightful.

We have prepared a short video covering this topic, or you can skip ahead to the written instructions below.

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## Setting Up Your Race for Analysis

Before you can analyze your performance, you need to properly define the race in ChartedSails:

### Step 1: Highlight the Race on the Timeline
- Find the approximate beginning of **the start sequence**
- Click and hold to make a selection around the entire race

### Step 2: Define the Start Line and Time
- Click the "Create Race" button
- ChartedSails automatically positions the start line using your GPS data
- To adjust the line: hover over a mark and drag it to the correct position
- To adjust the start time: click the time field and use arrow keys for second-by-second precision

### Step 3: Define the Race Course
- Click "Add Mark" to define each leg of the race
- ChartedSails estimates mark positions from your track, but you can adjust as needed
- A red track indicates a mark rounding issue - move the mark until the track flows smoothly around it

## Common Issues and Solutions

When defining your race course, you might encounter these common challenges:

- **Problem:** Red track indicates boat not reaching the mark
- **Solution:** Move the mark closer to where your boat actually rounded

- **Problem:** Track loops around mark multiple times
- **Solution:** Ensure you're placing the mark at the correct location where you actually rounded it

- **Problem:** Start line appears at wrong angle
- **Solution:** Use the rotation handle to adjust the angle of the start line

## Pro Tip

Set aside 15-30 minutes after each race day to define your races in ChartedSails while the details are fresh in your mind.

## What's Next?

Now that you've set up your race in ChartedSails, you're ready to extract valuable insights from the data. Continue to the next section to learn about [turning your race into numbers](/sailing-data-course/race-analysis) that you can use to improve your performance.


Analyzing Your Races

Now that you've defined your race in ChartedSails, you can extract valuable insights from the data. This section will show you how to navigate through your race data and understand the key metrics that can help you improve.



Now that you've defined your race in ChartedSails, you can extract valuable insights from the data. This section will show you how to navigate through your race data and understand the key metrics that can help you improve.

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## Navigating Through the Race

To begin analyzing your race data:

1. Click on the orange bar on the timeline that represents your race
2. ChartedSails will zoom in on the race and filter out any other data
3. All the numbers and metrics will now be exclusive to the race you're analyzing

## Analyzing the Start

The race start is critical - often determining your position for the entire race. Click on the starting sequence and select the Performance tool to access these key metrics:

**Key Start Metrics:**
- **Speed at the gun** - The faster the better. Too slow may indicate you were stuck beneath another boat or being overly cautious
- **Time and distance to line** - Should be as close to 0 as possible without crossing early
- **Speed at the line** - Should match your target speed for the conditions

**Beyond the Numbers:**
- Did you start on the favored end of the line?
- Had you correctly identified the favored side of the course?
- Did your start strategy work as planned?

**Action Step:** Add a comment on the timeline about your start. Was it good? If not, what specific problem occurred? Identifying areas to improve is the first step toward progress.

## Leg-by-Leg Analysis

Click on each leg on the timeline to focus on that specific portion of the race:

For each leg, ChartedSails shows:
- Distance sailed
- Average speed
- Maximum speed
- VMG to the next mark

**Questions to Ask:**
- What side of the course did you sail on, and why?
- Did the wind rotate during the leg? Did you spot and react to shifts?
- How many maneuvers did you execute? (Generally, fewer is better, but not at the expense of missing shifts)
- Did you pinch because you tacked too early?
- Did you overstay a mark and waste distance?
- Are your speed, wind angle, and heel angle on target?

## Overall Race Performance

After analyzing individual components, review your overall race performance:
- What was your average speed for the entire race?
- How does your total distance sailed compare to other races on the same course?
- If others shared their data, how do your metrics compare to theirs?

## Practical Example

Here's what leg analysis might reveal:

```
Upwind Leg 1:
- Distance sailed: 1.2 nautical miles
- VMG: 4.8 knots
- 3 tacks executed
- Wind shifted right 15° during leg
- Lost 0.3 knots of boat speed after second tack
```

This data might show that you responded well to the wind shift but need to work on speed recovery after tacks.

## Pro Tip

Focus on extracting 1-3 specific lessons from each race analysis session. Make notes about these points and create a plan to improve them in your next race.

Now that you understand how to analyze your race data, continue to [sharing sailing insights](/sailing-data-course/sharing-insights) to learn how to collaborate with your crew and other sailors.


Your Race in Numbers

Sailing is a team sport, and sharing insights with your crew, coach, or fellow competitors can accelerate everyone's learning. In this section, we'll explore how to effectively share your sailing data and insights using ChartedSails.

Practical Example: Effective Data Sharing



Sailing is a team sport, and sharing insights with your crew, coach, or fellow competitors can accelerate everyone's learning. In this section, we'll explore how to effectively share your sailing data and insights using ChartedSails.

## Sharing Options in ChartedSails

ChartedSails offers several ways to share your sailing data:

### Direct Sharing with Individual Users

![Share Dialog](/assets/sailing-data-course/share-session.png)

- Click the "Share" button in the top right corner of any session
- Enter the email addresses of the people you want to share with
- Choose whether they can view only or edit the session
- Add a personalized message with specific points to focus on

### Public Links

For sharing with people who don't have ChartedSails accounts, open the Share window and copy the public link.

Send the link via email or WhatsApp. Anyone with the link will be able to replay the sessions, take measurements and read the comments.


## Best Practices for Sharing

### For Skippers
- Share data immediately after racing while it's still relevant
- Highlight specific areas for crew members to focus on
- Include notes from your observations during the race
- Ask specific questions to guide crew feedback

### For Crews
- Look at the data before your debrief session
- Compare your perception with what the data shows
- Prepare specific questions for discussion
- Focus on areas relevant to your role (trimmer, tactician, etc.)

### For Training Groups
- Compare data across boats to identify different strategies
- Look for patterns in successful approaches
- Create a standard format for sharing observations
- Set up regular review sessions

## Practical Example: Effective Data Sharing

Here's an example of an effective sharing message:

```
Team,

I've shared today's races. Please focus on:

1. Race 2, upwind leg 1: We had good speed but lost ground on the right side.
Let's discuss the tactical decision at 14:32.

2. Race 3, start: Our timing was perfect but our speed was 0.5 knots below target at the gun. Check the trimming data.

3. All downwind legs: Compare our VMG with boat #42, who was consistently faster.

Please add your observations before our debrief tomorrow at 10 AM.
```

## Real-world examples

We compiled a selection of [really compelling debriefs](/blog/compelling-sailing-debriefs) on our blog. Read it for some inspiration!

## Pro Tip

When sharing data with coaches or mentors, be specific about what you want feedback on. Generic "what do you think?" questions are less effective than targeted questions like "How could we improve our speed recovery after tacks in race 2?"

Now that you understand how to share your sailing insights, continue to [using video for improvement](/sailing-data-course/improving-with-video) to learn how to enhance your data analysis with synchronized video.


Sharing Sailing Insights

In the heat of racing, it's impossible to notice all the minute details that contribute to your performance. Video changes everything by providing an objective view of what happened.



In the heat of racing, it's impossible to notice all the minute details that contribute to your performance. Video changes everything by providing an objective view of what happened.

With ChartedSails, you can synchronize video recordings with your sailing data, creating a powerful tool for improvement. Because the video is synchronized to your track, you can easily jump to specific moments - like the starting sequence of the second race, the first mark rounding, or the moment you hit your top speed.

## Adding Video to Your Replay

### Automatic Synchronization
1. Click the "Add Video" button in ChartedSails
2. Select your video file
3. ChartedSails will analyze your file and automatically detect the recording time
4. Your video will appear on the timeline at the correct position

The video and data replay are now synchronized. You can navigate through the video and simultaneously see:
- Your boat's position on the track
- Performance numbers
- Wind data
- Any other metrics you've enabled

### Supported Video Sources
- GoPro cameras
- iPhone and Android smartphones
- Most digital cameras with timestamp data
- Drone footage (with timestamp data)

## Making the Most of Video Analysis

Video is particularly valuable for analyzing:

### 1. Starting Sequences
- See your positioning relative to other boats
- Analyze your acceleration and timing
- Review your crew's pre-start routine

### 2. Mark Roundings
- Check your approach angle and positioning
- Analyze boat handling during the rounding
- Review crew coordination during sail changes

### 3. Sail Trim
- Assess sail shape in different conditions
- Compare trim settings with performance data
- Identify opportunities for improvement

### 4. Crew Work
- Evaluate movement and weight distribution
- Analyze crew coordination during maneuvers
- Review communication effectiveness

## Practical Tips for Sailing Videos

### Camera Placement
- **Bow mount:** Good for starts and upwind sailing
- **Stern mount:** Ideal for crew work and downwind sailing
- **Mast mount:** Excellent for sail trim analysis
- **Crew-mounted:** Captures specific roles and perspectives

### Recording Settings
- Use medium resolution (1080p) for manageable file sizes
- Set wide-angle view to capture more of the boat and surroundings
- For longer sessions, consider using time-lapse mode

## Managing Your Videos

ChartedSails does not upload your videos to the cloud. They remain on your computer, which allows you to sync many hours of video and access it immediately.

**Important:** When you close your browser or switch to another computer, ChartedSails cannot play your videos. They will be shown as grey bars on the timeline. To reattach them:
1. Drag and drop your files (or use the "Add Video" button)
2. They will immediately be available again
3. Any time synchronization adjustments are remembered

## Pro Tip

Continue to [organizing group debriefs](/sailing-data-course/group-debriefs) to learn how to use data and video effectively in team settings.


Using Video for Improvement

Organizing a data-driven debrief for a group - whether for a club event, regatta, or sailing clinic - can dramatically improve learning and performance. This section covers practical advice on how to capture, organize, and present the data to get the most out of group debriefing sessions.



Organizing a data-driven debrief for a group - whether for a club event, regatta, or sailing clinic - can dramatically improve learning and performance. This section covers practical advice on how to capture, organize, and present the data to get the most out of group debriefing sessions.

## Recording Data for Groups

Collecting data from multiple boats can be challenging, but with proper planning, it can become a routine part of successful sailing events.

### Common Approaches

#### 1. Race Management Integration

The optimal solution is using a race-management system compatible with ChartedSails:
- All boats are tracked in real-time
- Data is immediately available in ChartedSails
- No manual uploading required
- Currently available through Velocitek integration
- Contact ChartedSails for details on other supported systems

#### 2. Centralized Collection
Have sailors send their data to one organizer:
- Works well when sailors use devices with easy export (like Vakaros)
- Consider including data submission requirements in the Sailing Instructions
- Example: "All competitors must provide GPS tracks to the race committee within 30 minutes of returning to shore"
- Station a knowledgeable person on the dock to help sailors extract and submit data

#### 3. Loaner Devices
For coaching scenarios:
- Purchase several trackers to distribute to boats
- Hand them out at the beginning of the day
- Collect them at the end of the session
- Use ChartedSails' coach app to manage devices (contact us for details)

## Preparing the Debrief

The most effective debriefs focus on 3-5 key insights rather than attempting to review all data for all boats.

### During the Event
Take good notes throughout the day, including:
- Times of significant moments
- Wind direction and speed at different times
- Boat numbers and notable performances
- Tactical decisions that seemed successful/unsuccessful
- Rule situations that warrant review
- Course configurations and any changes

### Example Notes
```
1:45 - Only 3 boats on course, taking measurements of line
1:59 - Wind 290° @ 17kts
2:03 - Start of first race, boat end favored
2:16 - First mark - #307 squeezed between mark and two boats
2:18 - #278 went far left while fleet went right
2:20 - Left side of gate clearly favored
2:30 - 3 boats overstood the mark - wind shifting left to 260° @ 22kts
2:42 - Several boats broaching - #605 and #763 decided against spinnakers
```

### After the Event
1. Verify all boat data is available in ChartedSails
2. Create the races and define the courses
3. Review your notes and identify teaching moments
4. Highlight these moments in ChartedSails and add comments
5. Take screenshots of key situations for your presentation
6. Organize findings into logical sections (starts, upwind strategy, mark roundings, etc.)

## Running the Debrief

### In-Person Format
1. Start with an overview of the day's conditions and courses
2. Present 3-5 key insights using data visualizations
3. Include both successful and unsuccessful examples
4. Involve participants by asking questions
5. Allow time for questions and discussion
6. End with specific takeaways for future improvement

### Remote Format
For virtual debriefs:
1. Use screen sharing to show ChartedSails data
2. Consider recording the session for those who can't attend
3. Create a structured agenda and stick to it
4. Use polls or chat features to keep participants engaged
5. Share the ChartedSails link so sailors can explore on their own

## Publishing the Data

After the debrief:
1. Share the link to the session in ChartedSails with all participants
2. Include any presentation materials used during the debrief
3. Create a summary document of key learnings
4. Encourage participants to review their own data in detail

## Pro Tip

Create a template for your debrief presentations that includes:
- Weather conditions summary
- Course diagram
- Key metrics for each race
- Highlighted learning moments
- Action items for improvement

This standardized approach makes debriefs more efficient and helps sailors know what to expect.

## Conclusion

Creating a habit of data-driven debriefs is one of the most valuable aspects of sailing clinics and events. By teaching sailors how to collect, analyze, and learn from their data, you're providing benefits that extend far beyond the event itself.

Congratulations on completing the Sailing Data Analysis Course! You now have the knowledge to collect, analyze, and share sailing data effectively. Keep exploring and refining your skills, and don't hesitate to reach out if you have any questions.
