I’m working on my own kayak computer, and I would really appreciate your input.

I’ve always wanted to try building a sports computer, mainly because I don’t want to buy over-priced/under-performed products from the market. This project started as a casual hobby, but I’ve been putting more and more effort into it lately. And I’d love to get your thoughts to make it better.

The device I’m developing is multi-sport, covering kayaking, rowing, canoeing, SUP, cycling, and paragliding. I’ve tried to pack in the best possible hardware I can find, while still aiming for a MSRP under $400—please let me know if this seems reasonable:

A 3.5-inch touch-enabled color screen (TFT so it is perfectly viewable under direct sunlight)

Best IMU/Gyro/GPS sensor array with high fidelity and sampling rate

Monolithic shell for durability and IP67 waterproof (ideal for kayaking in various water conditions)

A big battery for longevity (no need to worry about power shortage during long kayaking trips)

For kayaking specifically, I’ve tried to include all the key functions I think are useful: stroke rate, stroke length, pace, boat speed, power, hull attitude. It can also connect to heart rate monitors for comprehensive fitness tracking—but I’m not sure if I’ve missed anything crucial. Do you have any suggestions for kayaking-specific features?