I know this has been discussed over the ages, just found out where the water was coming from. For some reason the back two drains in the cockpit floor run on top of the fuel tank, then the water runs forward and against the bulkhead seperating the cabin from the fuel tank. Over time the water rotted out the top of the bulkhead and delaminated the fiberglass. I can run a water hose near the cockpit drain and almost immediately see a waterfall into the cabin through exposed material I have removed. I dont know why the drains are not running into the engine bay easily. Maybe a blockage or maybe there needs to be water bulkheads added with dedicated drain line. I will most likely be pulling the gas tank to look for more damage and to replace the cabin bulkhead.

My 311 had plastic thru-hulls and then hoses that made sure the water drained to the bilge.

Prater,
Post pictures of the project if you remove the tank. Us that have been on here for many years have talk and researched this problem but nobody has ever shown pictures on the tank removal and the drainage system that does go from the the cabin to the engine compartment.

I have wondered where the water goes that drains from the cockpit. Like you said, they drain to the front of the engine compartment bulkhead. Formula Techs state that there is no way water can get under the floor or in to the cabin.

I have read that statement before, I had pulled the windshield and epoxied all the holes and then reinstalled. Checked the rub rail for leaks and could not figure out why water always made its way back in. Once I started to replace the floor I noticed rot damage everywhere so I decided to pull out the whole interior and start over. I removed some roted wood and fiberglass from the bulkhead under the cabin door and noticed it went to both sides of the cabin and all the way to the floor. I could only figure water was getting on top of the gas tank. Sure enough I tested the theory with the back drains and noticed the water coming forward and pouring through into the cabin. Its a mess but I can fix it. Just going to take some time. I will try to get pics, but it may take a while...

It looks like formula forgot to install the bulkheads on the floor drains. It looks like its designed for the bulkheads but no evidence they were ever there.

I have also read about this being a problem area, but I have not seen rain for months. Most of the time I use a Calif. Duster and bottle of spay cleaner/wax to clean the bow.
Point is, I don't get water hitting the boat from the top very offend.

Couple of pictures after the rotten stringers were removed. That fuel tank is a son of a gun to pull up off that floor. Be prepared to take some time to get it to un-seat. In this boat the floor drains flowed into the bilge in front of the motors as described in a post above. before we re-installed the fuel tank. we layed a piece of 1" conduit in the bottom of the hull connecting the bilge to the front under the the step in the cabin. Then in the back we put a rubber plug in it. IN the event the front ever gets wet for any reason, you can pull the rubber plug, and it will drain. This happened only one time when the filter assembly on the air conditioning cracked and filled the cuddy floor with water.









I'll try and find the before pics.

So what you guys are saying is there isnt a drain from the cabing to the bilge correct? So it collects and just fill sthe floor?
-Mike

There is no drain back, it has a pump to the bilge. The problem is the water intrusion in the area around the gas tank causing rot since it does not have a way to drain.

Do you have a pic of this pump or locations of it. Is it under the floor in the cockpit or cabin?
-Mike

I dont have a pic right now, I will take some pics when I get back home and started on more of the teardown. My pump is in the cabin under the step.