Marines in Force Recon are absolutely trained in direct action missions, and are capable of performing in combat situations, but that is not their primary role.

FORBES: Where Does Marine Force Recon Fit In The World Of Special Operations?

The problem is that another Marine unit, the Scout Snipers, performs deep reconnaissance and intelligence gathering too, just like Force Recon.

FORBES: Where Does Marine Force Recon Fit In The World Of Special Operations?

The water, and swimming, is a heavy component of being in Force Recon (they are Marines after all, we operate on the sea).

FORBES: Where Does Marine Force Recon Fit In The World Of Special Operations?