Boaters and especially drunk small boaters are a ubiquitous danger to us all. Anyone who thinks boarding s are not an effective deterrent but done simply to justify their existence is pretty cynical. I'm adverse to unnecessary government intrusion but I also dislike jerks acting stupid in a boat.
So maybe the government should deal with jerks acting stupid in a boat instead of conducting random searches. What you're supporting is no different from cops conducting random searches on cars and homes on land.