Ask Sail: Mystery Leak

Author:
Updated:
Original:

A MYSTERY LEAK ON THE HARD

Q: We have a 2004 31ft Catalina 310 that has an in-mast furling mainsail, and the mast is deck-stepped. Haulout is the first week of October, and by Thanksgiving water in the bilge is already climbing up the sides and back-filling toward the stern where it is manually pumped into a bucket for removal. From shortly after Thanksgiving to March the water is frozen solid and has reached an “alarming” level. The cables running through the mast into the bilge are for the antenna, anemometer, TV scanner and radar. Other owners with the same setup on a 32ft sailboat don’t have this problem with water ingress. What is causing this to happen every year during outside storage?

Kevin Redmond, Plainfield, IL

DON CASEY REPLIES

This is a problem that can only be diagnosed on site, and you will need to wait until the spring thaw. My first suspicion is that one or more of the wires you mention do not have effective drip loops where they enter the mast. A single wire entering the mast will often be sufficient to channel gallons of water into your bilge.

If you rule out openings in the mast as the source, then the leak (or leaks) must be through the deck. If you think you know where the water might be getting in—around the mast step, for example—flood just that area with water from a hose while watching below for a telltale trickle. A very bright light will help. If this confirms your suspicions, you will need to caulk or reconfigure as necessary to stop the water from entering.

If you cannot find the leak by flooding, the one sure-fire method I know is to pressurize the boat and check for escaping air with soapy water—just like checking a tire for a puncture. This requires closing all through-hulls and sealing all hatches and other openings with leaf-bag plastic and/or tape. Also, tape a garbage bag over a vent so it can inflate to confirm positive air pressure. Provide the pressure with a hose from the outlet side of a shop-vac, a leaf blower or an electric air mattress pump sealed through another vent or port. With the pressure source running and the indicator bag inflated, sponge soapy water around all hardware, and over every seam and joint. Anywhere the solution shows growing bubbles, air is leaking out, which likely means water is leaking in. Again, the fix is to clean and bed or caulk as necessary to reestablish a watertight seal.

Got a question for our experts? Send it to sailmail@sailmagazine.com

January  2018

Related

Waypoint.image.cd

Say No To Waypoints

Ever since they first appeared in my navigational toolbox decades ago I have been wary of waypoints. They certainly do seem helpful, these electronic flags we plant in the ether to guide us to where we want to go. But I noticed early on they also tend to distort our perception. ...read more

Lead-shutterstock_429247

A Cruise up Florida’s St. Johns River

The chart showed 45ft of vertical clearance, and I knew the boat should be able to pass under the bridge. Still, there was that nagging voice in my head that wouldn’t let me be. “What if your air draft calculations were wrong?” it said. “And if you’re just a little too high the ...read more

pic00

Installing a Helm Pod

Our 1987 Pearson project boat came with an elderly but functioning Raymarine chartplotter, located belowdecks at the nav station. Since I usually sail solo or doublehanded, it was of little use down there—it needed to be near the helm. When I decided to update the plotter along ...read more

Panamerican

Pan American Game Success

Team USA’s young sailors went to the quadrennial Pan-American Games in Lima, Peru this summer with high hopes, and returned with a good haul of medals—two Golds, three Silvers, and two Bronze. Gold medals went to Ernesto Rodriguez and Hallie Schiffman (Mixed Snipe) and Riley ...read more

190916-AC75

U.S. Team Launches First America’s Cup Boat

Fast forward to around 2:25 to see the boat in action. First day out and already doing full-foiling gybes: not too shabby! Hard on the heels of the unveiling of New Zealand’s first AC75, the New York Yacht Club’s American Magic team has now launched its first America’s Cup ...read more

GGTobCaysHorseshoeColors

Picking a Charter Destination

Picking a destination should reflect the interests of your group, says People often ask about my favorite charter destination, and invariably, I sidestep the question with one of my own: “Well, what do you want to do on your vacation?” Most often I hear an incredulous, “Why, ...read more

sinking

Waterlines: Chasing Leaks on Boats

Chasing leaks on boats is a time-honored obsession. Rule number one in all galaxies of the nautical universe through all of nautical history has always been the same: keep the water on the outside. When water somehow finds its way inside and you don’t know where it’s coming ...read more

BestBoatNominees2020-Promo

Best Boats Nominees 2020

Bring on the monohulls! In a world increasingly given over to multihull sailing, SAIL magazine’s “Best Boats” class of 2020 brings with it a strong new group of keelboats, including everything from luxury cruisers nipping at the heels of their mega-yacht brethren to a number of ...read more