1989 REVENGE 22: Purpose of Cabin Through-hull Drain

[burnett1]

Q1: [what is the] function [of the through hull drain located in the cabin area of a 1989 REVENGE 22]?

Q2: [is water dripping from the through-hull drain located in the cabin area of a 1989 REVENGE 22 an indication that the hull is] compromised?

Q3: can and should [the through-hull drain in the cabin area of a 1989 REVENGE 22] be plugged?

BACKSTORY
[I] purchased 1989 REVENGE 22. [I have] noticed two small holes drilled in forward cabin floor just after step down showing drips of water coming in. [I] pulled the boat [out of the water]. [Then I] noticed water dripping from the cabin through-hull opening at [the] bottom of the boat. [I am] not sure of its function. [I am] assuming [the drain is] allowing water in forward cabin.

[jimh]

Q1: [what is the] function [of the through hull drain located in the cabin area of a 1989 REVENGE 22]?

The through-hull drain located in a sump area in the cabin of a 1989 REVENGE 22 that is just forward of the step-down into the cabin is there to allow any water that has accumulated in the sump to be drained. Of course, when the boat is in the water, the through hull drain in the cabin sump MUST be plugged. However, when the boat is making forward headway, the drain can be opened and water will flow out to the sea.

The owner's manual explains the how to handle all the drains on the 1989 REVENGE 22. See the section "SELF BAILING AND DRAIN TUBES" in the OPERATIONS section of the manual for more advice.

If you do not have a printed copy of the owner's manual, you can use my on-line HTML version of the owner's manual, which is available in the REFERENCE section of the WHALER portion of the CONTINUOUSWAVE.COM website. See

https://continuouswave.com/whaler/refer ... nual18-25/

For advice on the drains, see the section at

https://continuouswave.com/whaler/refer ... elfBailing

[jimh]

[I have] noticed two small holes drilled in forward cabin floor just after step down showing drips of water coming in.

Generally I do not think there should be any holes in the gelcoat layer of the cabin floor in the area near the aft end of the cabin near the steps. Any holes in that area should be dried out and filled in to prevent water from seeping into the interior of the Unibond hull.

Post a clear photograph showing these holes so that readers can better understand what they might have been used for.

[burnett1]

[I] will [in the future provide pictures that show the location of the two holes].

Water is being trapped between the cabin deck floor and the bottom forward compartment bulkhead of the boat.

I discovered the small drilled holes when I removed the porta potty.

I am assuming [some unidentified person of male gender who has not been mentioned before in this discussion] did this to allow water to slowly escape [from from the] forward compartment bulkhead.

However this [unclear] does not fix the problem.

I am assuming the through-hull opening located on the bottom of boat below cabin is the culprit. I am not familiar with this type of through-hull or its hardware. but [I] am assuming it has been compromised and is allowing water in the lower hull.

Now that the boat is out of the water [there is] water dripping slowly out of that same through-hull fitting.

Your time [is] much appreciated.

—Andy

[jimh]

I discovered the small drilled holes when I removed the Porta-Potty

As I recall--I am working from memory here--if there were a marine toilet installed in the cabin of a c.1989 REVENGE 22, there would be a metal rod bracket formed into a shape to hold the toilet in place, and the bracket would be fastened to the floor or deck of the cabin using two self-tapping screws.

If you boat has open holes in the deck or floor in the cabin, the holes should have been immediately plugged with a sealant or resin as soon as the marine toilet bracket was removed. If you leave any openings in the gel coat layer of a Unibond hull, particularly in something like a low area or a sump area--which is exactly what the floor of the cabin will be if water is getting into that area--then you are allowing water to soak into the foam interior of the Unibond hull. That is never a good thing to permit to go on for any time at all.

[jimh]

...to allow water to slowly escape [from from the] forward compartment bulkhead.

I am not clear what you mean by the term "forward compartment bulkhead."

In a c.1989 REVENGE 22 there is a bulkhead at the forward end of the cabin that separates the cabin from the ANCHOR LOCKER. The anchor locker hatch is not particularly well-sealed, and, when an anchor and rode are hauled from the sea, the anchor locker will become quite wet. That is why there are drains in the anchor locker to permit any water in the locker to drain to the sea via two small through-hull openings. If the anchor locker drains are blocked--which can easily happen if the anchor was pulled from a muddy sea bed and not thoroughly washed before being put in the anchor locker--then mud can harden in those drains and block them. This will allow water to build up in the anchor locker.

The seal of the bulkhead between the anchor locker and the cabin is just a bead of caulk. The caulk was put in place in 1989, so it is now 36-years-old. Like any caulk that has been drying for 36-years, it could have shrunk. If the caulk is no longer creating a water-tight barrier between the anchor locker and the cabin, there is a very good probability that water will get into the cabin.

As mentioned above, if there are holes drilled into the cabin floor that were for screw fasteners that have been removed, that is a perfect path for water to get into the foam. Water flows downhill. Water could collect in the foam around the cabin sump through-hull drain.

Also, the cabin sump through-hull drain should be protected by having a cover over the leading edge of the drain. The purpose of the cover is to divert water coming across the hull at high speed and significant pressure from hitting the leading edge of the drain. The cover also enhances the Venturi effect so that when the boat is underway forward with some speed, any water in the cabin will rapidly drain when the sump is unplugged.

ASIDE: if you launch a REVENGE 22 with the cabin sump drain open to the sea, the cabin sump will rapidly fill with water. However, if you get underway and get the boat on plane, that water will drain out via the open drain to the sea, and the sump will completely dry out, at which time you can put the plug back in place. I have actually seen that done, although not on my REVENGE.

Check to see if the cabin sump through-hull drain opening on the bottom of the hull has a cover in place.

The cover is made from a small Perko clam shell vent fitting. Typically five fasteners hold the cover to the hull over the drain. The use of Perko clam shell vent fittings as covers for drains in mentioned in the FAQ answer to

Q12: How Are Brass Drain Tubes Replaced?
https://continuouswave.com/whaler/reference/FAQ/#Q12

Also note: if that drain clamshell cover is not there, there could be as many as five open holes in the hull, creating a beautiful place for high pressure water to get into the hull.