Yes, most of the Grosse Point shoreline is very shallow, and many spots rocky.

I've see boats in Geno's, but far from ideal conditions. The water depth is spotty, weeds can be pretty bad, and their docks are poor. You can get in there, but you have to know what you're doing, and be prepared to deal with the unstable docks. I live around the corner and won't take my boat there

You can also look at houses on the Clinton River for deep water. I own a house on the Clinton River (currently a rental since I’m out of state for work) but a few things about the river. Be careful where it is at since it’s no wake all the way. Some realtors advertise houses by mine saying “30min ride to the lake!” It takes 45-50min from my house. Still will have to check how the docks are set up and water levels at some houses, some places on the river are deeper than others. My dock extends 30ft from the seawall into the river. When water levels are low I have 1ft of water at the seawall and 3ft at the end of the dock. Normally I got 2ft at the wall and 4ft at the end of the dock.

All of the Grosse Pointes have private marinas for residents only. I believe the only one with limitations is the Woods with a length of 28ft.