I'm in the sewers part of the castle dungeon, at the point where according to the UESP I should swim through an underwater passage. Except I can't. If I don't crouch I'm too tall to fit through and if I do crouch I can't move. I I though that maybe I was carrying too much weight, but when I'm not crouching I can swim normally so I don't think that's it.

Anything I can do except use a hacking tool to give myself the bloody painting?

Well you could just enable cheat mode and use the "[" and"]" cheats, I guess.

You need to crouch and just keep trying to push through from different angles. I preferred the walkthrough at tesguides.com when I first played through the game. (At the time I found it better than the one that was on the uesp -- but the uesp is still updated occasionally.)

I tried the different angles but it didn't work. So I used cheat codes instead. Thanks for the help.

ugh.. the wayrest painting quest..

god knows how anyone found that back in the day.

Days and days of trial and error, followed by vowing to give up on Elder Scrolls forever and go play Diablo, then finally driving to the game store and buying the game guide.

Trial and error indeed. I think I spent a week IRL (amidst school, homework and gaming obviously) in that castle.

Bypass the sewer and go up 3 levels. Take the 2cnd right (where the 3 torches are) and walk across the corner of the trap door to open it. Levitate down 2 shafts, go up the stairs and you're at what Wiki calls the "window".

Casting "water walking" when swimming allows much easier movement through water.

Oh man, I remember all that being underwater.

It's a little late now, since I've already used the cheats to teleport straight to the painting. But your advice could come in handy for a future playthrough.