i know about the in-line filter/screen, and have cleaned it out as usual. but, i'm still not getting the shower to drain properly.
it seemed as though there is a clog between the shower drain itself and the pump, which is located under the galley sink. with that, as i couldn't get a plunger in the corner of the stall, i used...of all things...a sham-wow to stuff down the little opening in the drain to create a plunger effect, and when i did, the water began to get caught by the pump and drained. when i stopped "plunging", it stopped.
the pump is running, and again the filter/screen is clean, but it's a no-go.
i spoke with g3 last night who told me about an access opening near the shower drain/gally wall. unfortunately for me, the previous owner of my boat was apparently a bone-head and glued down wood flooring in the galley and lower cabin...covering up the access opening to both the shower drain and the center opening for the bilge.

in the hopes of NOT having to pull up the floor to get access to that opening, can anyone offer any other suggestions as to how to correct the problem?
any safe drain cleaners? drain sized nuclear explosives?