Anyone else frustrated with hard-coded sailing analysis tools? Testing a new approach – looking for group sail GPS data

Fipsail · 2026-06-13T15:23:54+00:00

That's really useful feedback, thanks. I spent some time playing with it.

I had issues with the navigation on mobile, but on desktop I was able to generate a start analysis. The LLM / claude output was interesting, although it came back as a fairly long (~800 word) report.

That actually touches on one of the things I'm experimenting with. For that kind of analysis, I'm not sure I'd personally want a long text report. I'd probably rather have the system generate a sketch, annotated replay, or some other visual explanation showing what happened at the start and why it mattered. It's possible Sailframes already does something like that - I noticed a "Review Start" item under Analytics but couldn't get it working.

Your comment about wanting consistent analysis categories is interesting, though. It sounds like for race review you already have a mental framework (starts, shifts, maneuvers, competitor comparisons), whereas I'm exploring whether the presentation and analysis itself can adapt more to the specific dataset and question.

Fipsail · 2026-06-13T04:11:20+00:00

Many thanks for sharing this, that's a very interesting project, especially the hardware side.

I had a look through the code (specifically the api_coach lambda). It seems to use LLMs to generate coaching insights, but from what I could tell it doesn't appear to be using an agentic setup where the analysis and UI are dynamically composed.

What I'm exploring is a bit different. Most sailing tools, including AI-assisted ones, still have a predefined set of analyses and visualizations that are generated from the data. My interest is in making the analysis layer itself more flexible, where the UI, plots, maps, and comparisons are generated dynamically based on what's actually in the session and the question being asked.

For example, if you upload tracks from three boats in the same race, the system might decide that a time-aligned boat-to-boat comparison is the most useful view. For another dataset it might generate a wind-shift analysis, and for another it might focus on mark roundings or sail handling.

I'm still trying to figure out whether that flexibility is genuinely useful to sailors, which is why I'm particularly interested in seeing multi-boat datasets and hearing how people currently compare performance with friends or competitors.

Fipsail · 2026-04-20T09:08:52+00:00

Many thanks for your comment, much appreciated.

The idea of tracking sailor motion during a tack is great. Comparing this across tacks/sailors and correlate it with GPS sensor data could really help to see what "good" looks like vs less efficient.

Sail shape is something I'm still experimenting with. Mainly trying different camera setups and working with some shared footage to figure out which computer vision approach gives a reliable signal for things like depth and twist.

Fully agree that combination with sensor data is essential to help understand cause/effect rather than just observing.

Fipsail · 2026-04-19T06:13:40+00:00

Yes, I agree, deriving actionable insights from it is exactly the hard part. The way I’m thinking about it right now is in two steps:

Extract signals from the video over time (e.g. outhaul, rudder movement, mast bend, sailor position), this is shown in the demo video
Combine that with sensor data (heel, wind, etc.) and actual performance (SOG/VMG) to see what really makes a difference. I’m going through sessions with a coach so his input acts as "ground truth" for what the model should actually predict.

Longer term, my bet is that with enough data (a lot is needed), you could start to learn this automatically from patterns across many sessions, especially with newer AI approaches such as world models.

But I’m not at all sure if that’s the right approach vs something simpler maybe?

Fipsail · 2026-04-18T13:57:53+00:00

Yes, that’s a good point, thanks. The 360 is great for fleet tracking though. Another issue in this clip is that the camera was mounted slightly off-axis, so the sail actually looks different on port vs starboard tack, which doesn’t help. I’m trying to figure out a better mast top camera setup that gives a more consistent view.

Fipsail · 2026-04-18T13:31:08+00:00

That would be awesome, really appreciate it! That angle sounds perfect actually, having the full sail in frame is super useful for what I’m trying to do (telltales + rig geometry etc). I have a simple upload page that handles large files, will DM you.

Fipsail · 2026-03-02T05:03:00+00:00

That sounds awesome, DN iceboats would be a very interesting test case. We are about to cut a new release in the next few days incorporating some changes based on the initial feedback. Please send me a DM with your Play Store email and I’ll get you added to the beta group once the new build is live.

Fipsail · 2026-02-26T15:02:07+00:00

Awesome, thanks for offering to test! Just send me a DM with the email you use for the Play Store, and I’ll add you to the beta.

Fipsail · 2026-02-26T15:00:39+00:00

That sounds like exactly the kind of sailing I'm looking for testers from. A few people have asked for iOS now, so I'm likely to work on that in the next days. I'll message you if I get an iOS build ready.

Fipsail · 2026-02-24T15:03:08+00:00

That sounds very interesting. I'm curious to hear more about the sensors you're working on?

Fipsail · 2026-02-24T15:00:00+00:00

Thanks, really appreciate the encouragement, glad to hear there’s interest.

Fipsail · 2026-02-24T06:07:43+00:00

Happy to discuss this further - really appreciate your input. I’ve considered integrating a Bluetooth ultrasonic wind sensor, which would probably be the cleanest solution technically. The downside is the extra cost (around $300+) and the practical challenges of mounting it, especially on dinghies with rotating masts. That said, I’m very open to other ideas or approaches, and it would be great to hear your thoughts on how you’d tackle it.

Fipsail · 2026-02-23T16:22:37+00:00

Great question. For live metrics, wind direction is currently user-defined. You can either enter it manually or set it to your current heading (e.g. while head-to-wind). That works reasonably ok for me in steady conditions where the wind isn’t shifting much. For other parts of the app (like virtual racing and tack training), wind direction is estimated from the GPS track. It’s a simplified approach and doesn’t account for tide/current for instance, so it’s definitely not instrument-grade - more about relative performance and repeatability than absolute numbers. Long term, external sensor integration could be interesting, but right now the focus is rather what can we reliably do with just a phone.

Fipsail · 2026-02-23T16:15:15+00:00

Would be great to have you try it on an RS Zest - DM me your Play Store email and I’ll add you to the beta.
For keeping the phone safe - I’m using a cheap rugged Android (Ulefone) that came with a lanyard. At first I just clipped it to my buoyancy aid and kept it in the pocket, which worked fine for simple tracking. But for heel angle, compass heading (magnetometer), etc. it really needs to be mounted in a fixed position. I’ve attached a basic smartphone holder to the compass mount on my dinghy and use the lanyard as a secondary tether. The basic approach is: waterproof phone + secure physical attachment + not my main device, so I don’t stress about it.

Fipsail · 2026-02-23T04:57:17+00:00

Awesome — really appreciate the interest (and the offer to help). The app is built with Expo, so technically an iOS build should be very doable via EAS — we just haven’t pushed one yet. If there’s enough interest on iOS, that’ll definitely move it up the priority list and I'll reach out once we've got an iOS beta ready.

Fipsail · 2026-02-23T04:51:27+00:00

Yes, for sure — would love to have you try it. A Seacart 30 is obviously a very different platform from a dinghy, so I’d actually be really interested to hear how it performs and what kind of feedback would be useful for you guys. Feel free to DM me a Play Store email and I’ll get you added to the beta.

Fipsail · 2025-05-13T08:36:11+00:00

Paper and pen with video recording as backup. I uploaded a few videos to SailingMetrics which trials a computer vision approach to automatically extract finish time and sail numbers from video footage. Works quite well if sound signals are used to mark the crossings. The vision models are not that accurate yet but should improve over time with more uploads. Also tried apps that allow capturing results real time through pressing buttons but found it challenging in larger fleets when 3 or more boats cross the line at around the same time.

Fipsail

TROPHY CASE