Unfortunately, thanks to the wonders of finishing a boat with a fiberglass liner, I have no access to the back side of the sump. When that hose needs replacement it's going to involve cutting the pan and insetting an aftermarket sump assembly. So I'm praying a collapsed hose is not my issue, and that job will be for a future owner.

Will try snaking the hose and/or flushing. I also have a rebuild kit on order. The boat's a 2001 so it wouldn't surprise me if the pump needs a rebuild. I'll do it anyway as PM.