Water in Prindle 18 hulls

Check the jib traveler wire where it enters the hull at the inspection ports.
Check the rubber bungs under the rear cross beam.
Remove and reseal the inspection ports bases themselves.
one of my P18's although it looked ok from outside the the silicon under the deck port had separated from the hull and was not sealing.

I would remove both beams and clean the saddles. Put a bead of silicone and reinstall. Do not tighten all the way at first. Allow the silicone to set up for 24 hours and then tighten. That will give you a better seal, the set up silicone will act like a gasket. Use the same method for the inspection ports. Check the plugs in the rear beam under the tramp and seal if necessary. Remove the rudder gudgens and drain plug fittings , clean and reseal, also wait 24 hours before tightening all the way. It may sound like a lot of work, but it can be done in about 4 hours and is well woth the time. Check the beam bolts after sailing a few time as they will need to be retightened. They normally seat real good after a few times.

I also forgot to mention that when I reseal the inspection ports that I replace the screws with bolts, washers and nylon locking nuts. The screws tend to loosen after time and can not be properly retightened.

Scott,
For clarity, when you say

while it is beached. Takes on very little water while sailing.

you mean while it is stored on the beach, as in it gets rained on and takes in water over a period of days or weeks, right?

Did you try the soap test? Make some really soapy water (hand dishwater soap) in a spray bottle and spray the portholes and crossbar beds real well and then blow (with your mouth) into the open drain plug and have a partner look for bubbles. If no bubbles, spray the other areas mentioned in this thread, and keep looking.

tahoeprindle18 wrote: Check the rubber bungs under the rear cross beam.

I was told these do not actually go into the hull. They provide access to the bolt for the beam but it is a very small separate compartment from the hull. it only holds about a cup of water. You can sail without the rubber plugs in and not take on water.

Quarath wrote: [quote=tahoeprindle18]Check the rubber bungs under the rear cross beam.

I was told these do not actually go into the hull. They provide access to the bolt for the beam but it is a very small separate compartment from the hull. it only holds about a cup of water. You can sail without the rubber plugs in and not take on water.

The pockets on mine have open access to the inside of the main hulls on the ends. This may be the result of poor layup when they were built or may be how they were designed. either way I was getting water into my hulls when I still had the old stock plugs in place. Replaced the plugs with new plugs from Murray's and sealed the seams at the edges.

We had a problem with ours taking on water and it turned out that the area where the tramp attaches to the sides was where the water was getting in from. We sealed it up and have been good since. Might want to check there.