Found better sealed housing.
Housing will be mounted below SUP with cords.
Now swapping some pins in HW and SW for easier PCB routing.
-App sends commands by UDP
-add function to set colour based on orientation
-antenna will be as close as possible to the top with minimum water between.

#arduino

Thanks!
Found proper components in my office shelf. Funny!

I use a very similar mobile setup to visualize meeting room air quality.
Better add a low power controller and switch on power of the sensors and ESP every 5-60min. That will reduce required battery size.
You could start with a passive PCB backplane to simply connect all your modules.