Originally posted by The n00b A:

They dont prevent the sea from bashing your boat against the shore repeatetly unless you "park it" in a river

If you have some wood you can just lock your boat in place relatively easily using the 45° pieces.

If it is really such a big issue you can also just stand at the mast of your boat and hack it with an axe, you will pick up the nails when it gets destroyed before they can sink and it is doable relatively quickly.