Go Pro Hero 8. Expensive but I 100% vouch for it and here is why.
I use it on my baja racetruck. I had a hero 7 with stabilization (which was nice) but once I put the 8 on it was night and day. UNREAL difference.
Granted I just got my SeaRider RIB 3 days ago so I have not tried it on a boat but if it can stabilize a offroad baja race trucks footage at 80-120 mph then it can stabilize a boat video.
There is a clip on zoom also if you see whales or whatever you want to video/take pics of closer.
Here was Andy Mcmillans Hero 7 on a trophy truck. These trucks rail 6 ft+ whoops at 70-120+ mph and it stays stabil. Look at the wheels in the wheel well bouncing around like crazy and you'll realize how good the stabilization is.
I'll try to find some Hero 8 and post soon. But even the 7 would be great on a boat. Wide angle, Superwide, etc...