Unknown plumbing?
The foward sink drain line exits the boat via a small thru-hull above the water line. The only problems here are possibly a broken thru-hull or drain line (clamps too). You should pump out the bilges getting as much water as possible out. I say bilges, because you want to also get out the water between the actual inner liner and the hull. Then put some colored water in the sink and allow it to drain. You may have to do this several times. You should see the water flow out the thru-hull above the water line. Check you bilges after a few minutes to see if the colored water has found a leak in the drain line/fittings inside the boat. On the valves not to open question, lets back up to what kind of valves you have. If your boat was made similar to mine, you should have two 1-1/2" valves, one under the galley sink and one in the area beneath the v-berth next to the bulkhead between the head and the v-berth. You should have two 1/2" valves, one for the inlet water to the engine (located underthe front edge of the engine) and another of inlet water to the head (located next to the head drain under the v-berth. Mine were all gate valves. If you have these replace them with ball valves at your earliest conveinence. I keep al valves closed unless they are in use. They all have the potential to sink your boat. Also I would have someone knowledgable check the plumbing setup on the head. Proper placement of the lines, venting, etc is critical. I'm sure you Peggy, The Head Mistress can help in this area. My boat does not have a water heater, so maybe someone else will answer that question. If you are going to do it, DO IT RIGHT!
