For years, the center storage area under the V berth in my 1983-built 3270 Bayliner accumulated water. Sometimes the hull liner around the door to the chainlocker (above the mattress) would be damp but never actually wet.
The leak finally went away when I had the chain locker drain hole enlarged and properly sealed.
When Bayliner built the boat, they simply drilled a half-inch hole through the hull (see photo) and didn’t seal it. The water from the chain locker ran down inside the hull fiberglass and seeped out the hairline cracks in the storage area under the berth. Fortunately the hull is entirely chopper-gun constructed so there's nothing to rot. The water had just been seeping through.
The photo is of the original drain hole and was taken looking down at the bottom of the chain locker. The drain hole is on the port side.
Other than normal condensation, the storage area has remained perfectly dry ever since the drain hole was repaired.
Since the bottom of the enlarged hole is now flush with the bottom of the locker, it now drains properly. The larger hole also allows a lot of the debris to escape.
Note: Years ago I had glassed the inside (forward) bottom of the bulkhead containing the wicker access door (to the storage area) to contain the water that leaked into the storage area. Prior to this, the water was flowing aft under the galley floor. I don't know where it would have ended up but having the underside of the galley floor constantly wet could not have been good.