For some reason it gives error that there is nothing to remove or you are too far when you place foundation under water in shallow waters and can't remove it even if you stand on it and crouch and try. This issue is only with really shallow waters, in any deeper this don't happen or if foundation is above water, only when foundation is just under water.

yeah can confirm but i never noticed it before and i use /remove all the time
I think its because its actually below the water line.

Updated. lol