Looking for suggestions for GPS

I've been thinking of getting a handheld GPS for use on my Wave.

The small bay out front of my house is guarded with a shallow shoal from the middle to the north end. The southern half is littered with big rocks lurking just below the surface. Using my SUP I have found a way out through the rocks and placed a few floating markers. Trouble is the markers can be hard to see in certain conditions. The path narrows down to about 20' wide in a couple places. Some wind directions make it easy, others not so much. A few directions I don't even try.

Would a GPS be accurate enough to mark some rocks as waypoints to help "thread the needle" in and out?

The compass and speed feature would also be handy.

I was also thinking of mounting it in a pouch fastened around my thigh, so it would be close at hand, but not out of reach. Is anybody else doing this? Or is this idea way out in left field?

Thanks in advance for the advice.

Can tell you what not to buy:
1. Handheld Garmin with lanyard in general. The plastic part where lanyard attaches is too flimsy, and GPS itself have habit to stuck in tramp lacing. Small pull on lanyard - GPS goes down.
2. Garmin Fenix I and II - harder to drown (wristworn ), but not accurate enough especially for your purpose.

IMHO try to make marks more visible, use taller buoys if possible/allowed.