in times of war.. not only will be the seabed be littered with
natural obstacles.. to defend a beach, opposition will also
deliberately throw in obstacles to hinder forces moving in..
that's when the role of divers come in.. they would move in before
hand to search for obstacles, mark them, plant TNT on them, and
detonate b4 guards do their beaching....
so by the time guards are beaching, the seabed is clear, and FCUs
and FCEPs can head allll the way into beach and not be stuck
outside in knee height waters..
for more info.. google on UDT or read on ops on beach Nomandy,
France WWII