The proximity of -ich to Netherlands suggests it may be the closest to the Dutch -wick and the English -wich.
There are cognate suffixes in the German-speaking areas (ending on -wyk, -wik, -wig, etc.) but -ich is not one of them. German -ich is equivalent to -ik in Dutch-speaking areas.
Wick is not a word that I know of, do you mean Wijk (neighborhood)? Like Noordwijk en Katwijk? Because that's almost certainly not related to 'bay'. Many coastal towns are named something with a 'dam' however (Amsterdam, Rotterdam, Monnikedam).