It's been a while since I went fishing down there, but I think I know what you're talking about.
First I'm assuming an older J/30 before they went to the 5 berth / L galley model.
If you take off the companionway steps, you'll see the hull liner, which is a large molded piece of glass that consists of the tracks the front steps sit in, the pan under the engine, the engine mounts, and the sides of the two quarterberths. The liner sets on top of the inside surface of the hull itself.
I'm guessing the phone fell into the quarterberth in the gap between the battery and the engine? If so, it may be under the liner under the engine. Good luck getting it out!
The engine mounts themselves, at least on my boat, have large holes cut on the inboard sides. It may be possible to reach an arm under the engine, in through one of those holes, and into the space between the hull and the liner and poke around for it.
Otherwise, a bent piece of stiff wire is great for fishing stuff out of tight places.
As far as drainage goes... it doesn't! Seriously.... I've had times where I get water down there. (I'm guessing a leaky icebox hose?) The water sloshes around freely under the engine pan, and it can even get to the storage areas underneath each quarterberth if there's enough of it. I can't figure out where it's supposed to drain. Nobody on this board has an answer, and I've tried TPI and Rod Johnstone without success. I don't know if it's supposed to drain somewhere but is clogged, or even if it was designed to have drainage in the first place! As much as I want it fixed, I'm guessing it would take ripping up the floorboards and filler between the bilge and the engine, and that's a bit more than I'm comfortable doing....
Good luck getting your phone back!
