March 15, 2009
That Sinking Feeling

By Tom Morkin

Watching the Pacific Ocean gush through a two-inch hole in the bottom of our boat, after the failure and loss of a two-inch through-hull, ranks right up there with the most traumatic events in our sailing lives. It certainly was the closest we’ve come to sinking our boat and it was only through good luck that Feel Free didn’t end up on the sea floor. Although it happened 10 years ago, the memory is still fresh and the impact it had on us borders on profound.

Like all near-catastrophes with boats, there were a number of valuable lessons learned. The near sinking drama not only highlighted mistakes we made that resulted in the through-hull failure, it also clearly illustrated how woefully ill prepared we were to deal with our sinking boat that had a hole in it.

Sinking is often the last thing on one’s mind when sailing along on a beautiful day.

So, dear reader, allow me to put you on board Feel Free on that memorable day in the hope that our brush with disaster may allow you to learn something from our mistakes and lack of preparation; if nothing else, you may find it mildly entertaining.

It was 0800, April 1999, in Tenacatita Bay on Mexico’s Pacific Coast. We were anchored in 35 feet of water. In 45 minutes, we were to meet good buddies John and Kottie of Sky II for a full day dinghy excursion, far from our anchored boats.

“Wait a minute, Liz,” I said. “What’s that trickling sound coming from the engine room? Hey, there’s water in the bilge and the bilge pump is on. Is it fresh water or salt water? Maybe it’s just a leak in a fresh water hose. Liz, turn the water pump off! No that’s not it.” I could still hear water hissing.
Flashlight in hand, I saw a major stream of water running along the hull. Following it upstream, to my horror, I saw that it was coming from one of the two two-inch cockpit-scupper through hulls and it was no longer trickling, it was gushing!  “Quick, close the sea cock! OH NO! The water is gushing in BETWEEN THE THROUGH-HULL LOCKNUT AND THE HULL! This cannot be happening, not to our boat!”

This is very serious… We are not insured. This could change our cruising plans... No, this could FINISH our cruising plans. What if the bilge pump fails? – These were among the thoughts racing through my mind within a couple of seconds of our dismal and shocking discovery.

“BUNGS... Where are the bungs? Oh, there they are. What size do I need? Liz! Get my mask and snorkel. I’ll put the bung in from the outside!”– and over the side I went.

Where the hell is that through-hull? A-ha, there it is... Ohmygawd! There is no through-hull! It’s gone! It broke and fell off! –  and, worse than that, the bung wouldn’t fit. The hole was too big.

 “Liz! Bigger bung and a rag!” That worked, and with them in place the water ingress was back to a trickle. The water level was still rising in the bilge but the bilge pump was pumping well.
 

Tom leaped over the side with mask and snorkel to make the shocking discovery that the two-inch through-hull was gone. With the combination of a bung and a rag he managed to temporarily stop the flow of water into the boat. (Drawing by Liz)

“Tom! Why is the cockpit filling with water?” Liz called frantically as she bailed water out.
 
Of course! The bilge pump discharges into the hose leading to the failed through-hull that also services one of two cockpit scuppers. We’re circulating water from the bilge to the cockpit and back to the bilge. Close the seacock! Great! Now the water backs up the hose to the cockpit where it drains through the second cockpit scupper. Oily bilge water then left a slippery, oily slick on the cockpit sole.

When John from Sky II arrived, we tried unsuccessfully to stop the inflow of water from the inside, but the hydraulic pressure resulting from a hole in the boat (even though a bung was in place) three feet below the waterline was just too great. It appeared our best course of action in the short term was to seal the hole from the outside.

The already-placed bung suffered two shortcomings: 1) it was too long, and 2) its sides needed to be sanded smooth to better fit the hole. Fortunately, we had another large bung on board that John cut and sanded until it was a good snug fit without too much of the wood protruding out from the hull.

We were 140 nautical miles from a haulout facility in Puerto Vallarta. We couldn’t go to sea without confidence the bung would stay in place. The situation called for an under water setting epoxy putty, something not carried onboard Feel Free or Sky II. It was a longshot but Liz dinghied over to one of the two other boats in the anchorage to see if they might have anything that might help us out. To our considerable surprise and delight, Liz returned with a one quart kit of Splash Zone underwater setting epoxy putty. It was one of those “cruisers helping cruisers” situations where Mike and Cecilia on Paragon, upon hearing of our plight, offered up $60 worth of precious repair material to people they’d never met.
 
The two-part putty was mixed one-to-one, slathered on the newly sanded bung and pushed into place from the outside. Hallelujah!

Tom mixed the two-part underwater-setting epoxy putty (provided by the kind folks on Paragon), slathered it on the bung, went over the side and pushed it into the hole in the hull to seal it, preventing water from entering the boat.

The crisis behind us, we inevitably started the “what if” game. What if we had been ashore when it happened? The boat almost surely would have gone to the bottom. Our batteries couldn’t have handled the bilge pump working to keep up with a two-inch hole for five hours. What if we’d been at sea? At night? In heaving seas? But it didn’t happen that way. It happened when we were on board in a quiet anchorage during daylight hours, surrounded by helpful friends.

The return to Puerto Vallarta was uneventful and provided time to reconsider our boat’s plumbing. Needless to say, the remaining through-hulls were called into question, particularly the ones in the vicinity of the failed through-hull, the assumption being that if electrolysis caused the failure, other through-hulls in the area would be vulnerable.

And why did we lose a through-hull? We suspect the through-hull to have been original boat gear, possibly 26 years old at the time. We also suspect that there may have been stray current running through the boat. Incidentally, the boat is not bonded but has two large zincs bolted to her externally mounted lead keel. We had hauled the boat two months earlier and checked and lubricated all sea cocks. Less attention was paid to the through-hulls but a visible check showed no pitting at the time of haulout. Our experience made us question the need for so many of our through-hulls to be under water.

After examining the boat’s plumbing system, we decided that the through-hulls servicing the deck drains and three sinks didn’t need to be under the waterline at all. So after a week of deliberating, we cut six holes in the lovely hull above the waterline, fitted a through-hull on each and re-plumbed the deck drains and sinks. We were thereby able to seal off six underwater through-hulls. We now have nine holes in the bottom of our boat instead of 15. It’s still a lot but six fewer than before. By the way, the nine holes are the following: forward head (2 holes), aft head (2 holes), engine water intake (1), cockpit scupper (1), rudder shaft (1), prop shaft (1), impeller for knot meter (1).

Like all near disasters on boats, ours was an intense learning experience. We learned not to take the flotation of our boat for granted. We learned the necessity of paying better attention to our boat’s plumbing system. Our experience illustrated the need to keep some basic materials on board that can be used in the event of another such problem. Previously established procedures for dealing with plumbing failures should be discussed and understood by all crew members. It is hoped that our lessons learned will ensure that history does not repeat itself on Feel Free and we hope that readers benefit from our experience and never have to experience for themselves… that sinking feeling!

Lessons Learned

• Naturally, we will more diligently check not only sea cocks but also through-hulls at every haulout. We will sand bottom paint off and look for pitting, and replace through-hulls periodically (every five years).
• We won’t leave port without an underwater setting epoxy – minimum one-quart or one-liter kit.
• All through-hulls should be easily accessible and a schematic diagram showing their locations, posted on board. The crew should be able to check all through-hulls and sea cocks easily and quickly without having to move mountains of gear.
• A properly fitting bung should be attached to each through-hull.
• Some other useful items to have on board:
• Plunger – placed over the hole on the outside, stops the water immediately, and provides time to affect a repair
• Long-haired mop – apparently, good on holes with ragged edges, inserted in hole from the inside. Mop hairs are compacted by twisting, inserting as much of the mop into the hole as possible. Water pressure will force strands against the irregular surface and slow water penetration.
• Toilet-seal wax – this is a ring of wax used to seal toilet bases to floors. The wax is moldable and could be used to seal the area around a propeller shaft should a repair to the stern-tube hose be necessary. Moldable rubber sealant used to seal windscreens in cars and trucks serves the same purpose.

Now, a properly fitting bung is attached to each of Feel Free’s through-hulls.

All hoses should be double hose-clamped to each fitting and connection with all stainless steel hose clamps.

• In addition to an adequate number of bilge pumps, consideration should be given to audio bilge pump alarms that are loud enough to be heard over the engine noise. This will ensure speedy recognition of a problem.

With Kottie and John of SKY II we enjoyed a drink on the beach at Tenacatita Bay after the crisis had passed, and talked about “Lessons learned