Simple GPS-enabled fitness band for rowing on the sea

Hi everyone,
I’ve been rowing on the sea as a hobby and I want to track my workouts. I have a Huawei GT2, but it only works for indoor rowing and doesn’t record GPS.

I can’t take my phone with me, so I need a fitness band or watch with built-in GPS that can track rowing.

I’m looking for something simple and not too expensive.

Or is there any way to track with my GT2 ?

Any suggestions? Thanks a lot!