I have 3 oversized Intakes....main, genset, a/c & raw water feed. No external screens.
Only 1 blockage when 3 small fish swam up the inrake. Cleared in 3 minutes from the inside of the boat. That is in the last 10, 000 miles of inland waterway cruising.
As has been posted...oversize the thru hulls and the suction force is minimized.