Please select your home edition
Edition
RS Sailing 2021 - LEADERBOARD

Changing a thru hull / ball valve at sea

by SV Crystal Blues 8 Jan 2018 19:19 UTC
Diver Ryan was faster and cheaper than a haul out © Neil Langford / SV Crystal Blues

We've done this a couple of times now, and it's a really simple and fast maintenance job. Finding a dripping leak in a ball valve on the engine sea water inlet, we investigated and found it was seeping through the seal to the handle. It had given us 15 years of service, so I was happy to replace it. We located the spares we carry and selected the right size - 1.25" in this case.

Next we needed a diver, and in chilly St. Augustine that was not going to be the Admiral. No way said she! A call to the local cruiser's net identified a willing local, so we scheduled the job for the next day at slack tide. Note that Crystal Blues has skin fittings (thru hulls) with stand pipes that are threaded, to allow the ball valves to be screwed on and off, without actually effecting the skin fitting.

Diver Ryan arrived right on time, and as he prepared his gear and suited up I started on my own work sequence :

  • Close the faulty valve and loosen the hose clamps on the hose connected to it.

  • With the hose clamps out of the way the hose tail (hose barb) is unscrewed from the valve. It rotates easily inside the hose, meaning you don't ever have to fight to actually get the hose off the hose tail. This is made easier if you always apply a little silicone sealant to the hose tail during assembly, before sliding the hose over it.

  • Once the hose tail is disconnected the action begins, Ryan the diver enters the water with our trusty toilet plunger and holds it over the water entry point. He taps three times on the hull to signal he's ready, and I open the ball valve - voila, just a tiny amount of water enters the boat, before the pressure differential forces the plunger tightly against the hull and seals the entry.

  • Unscrew the old ball valve, clean up the threads on the stand pipe, apply new PTFE tape and then screw on the new valve. Close the valve, tap three times on the hull and the diver removes the plunger. Simple!

  • Some time later I re-attached the hose tail and re-fastened the hose clamps. Job done.
While many older boats still have skin fittings that incorporate the valve, many newer vessels are built with separate components which allows this process to work just fine. From my perspective, $80 for a diver for 30 minutes is a lot better than $800 for a haul out, just to change a ball valve.

This article has been provided by the courtesy of SV Crystal Blues.

Related Articles

Rooster Sailing's 2025 Collection Just Dropped
From the redesigned Technical Shorts to the all-new SB2 Deck Trainers From the redesigned Technical Shorts to the all-new SB2 Deck Trainers, the 2025 collection has been developed with real sailors, for real conditions. Posted today at 4:00 pm
10 years of MidsummerSail
The 2025 edition will feature the largest fleet in the race's history The Agora direct MidsummerSail, the legendary nonstop offshore race from Wismar to the far north of Sweden, is celebrating its 10th anniversary this year, and breaking all previous records. Posted today at 2:26 pm
High-speed showdown in New York this weekend
Switzerland SailGP Team takes on the Big Apple Switzerland SailGP Team is back in action this weekend, racing at the iconic Mubadala New York Sail Grand Prix, 7 - 8 June. Posted today at 12:49 pm
Wally presents the new wallyrocket71
At the Loro Piana Giraglia 2025 On the occasion of the 2025 edition of the Loro Piana Giraglia, Wally is proud to introduce the brand new wallyrocket71. Posted today at 11:22 am
2025 Santa Maria Cup in Annapolis, USA Day 2
Final four skippers emerge from a competitive qualifying double-round robin stage A thrilling second day of racing at the 2025 Santa Maria Cup saw the final four skippers emerge from a competitive qualifying double-round robin stage. Posted today at 4:47 am
SailGP to Kick Off Summer in New York
With this Weekend's Mubadala New York Sail Grand Prix An unforgettable weekend of high-speed, close-to-shore racing and world-class entertainment will take place this weekend when the Mubadala New York Sail Grand Prix takes place in front of the most famous skyline in the world. Posted on 5 Jun
Scandinavian Gold Cup at Sopot, Poland Day 1
A slow start with very little wind The Scandinavian Gold Cup opened Thursday in Sopot, Poland, with seven 5.5 Metres competing for this historic and iconic trophy that dates back to 1922. Unfortunately, there was not enough wind to even complete one race. Posted on 5 Jun
49er, 49erFX and Nacra 17 Europeans Day 3
A six-hour bake on the water Veteran and multi-Olympic race officer Sulis was clear at the morning briefing, "Our priority is to get three races for the 49er so they can progress to the gold fleet." Posted on 5 Jun
Galicia 52 Super Series Royal Cup Day 3
Platoon Aviation turn up the heat but don't dent American Magic Quantum Racing's lead After a disappointing first regatta of the season when they finished in an uncharacteristic last position in Saint-Tropez, the fortunes of the German flagged 2023 52 SUPER SERIES overall champions Platoon Aviation seem to have turned for the better. Posted on 5 Jun
Diverse international fleet for 5th AEGEAN 600
The race start is a little over 1 month away In a sign that this newest of the world's 600-mile classic offshore races has reached maturity, organizers from the Hellenic Offshore Racing Club are pleased to announce yet another large international fleet will be assembled for the 2025 AEGEAN 600. Posted on 5 Jun
North Sails Loft 57 PodcastVaikobi 2024 DecemberSea Sure 2025