Check your boat’s plumbing, pumps, skin fittings and hatches to prevent going down at sea
A dramatic first-hand report over the weekend of a near-sinking of a trailerboat while fishing at Browns Mountain, 40km offshore from Sydney, highlights the need to check your boat’s plumbing, hatches and skin fittings for leaks, water ingress and high-risk points of failure.
As we have mentioned on our sites previously, repeating the call from rescue and safety authorities, those screw-on access ports commonly fitted to many boats and located in splash wells can be a danger area.
It is not uncommon for plastic hatch lids to distort or crack, for rubber o-rings to deteriorate, threads to burr and seals to leak water over time.
Not that long ago, the South Australian government issued a warning about spin-out inspection hatches after a fatality from a capsized boat was linked to its destabilisation caused by just such a leaking hatch.
Indeed, it appears that the recent near-sinking of a trailerboat at Browns Mountain could have been due to some spin-off hatches in the splash well that were leaking. We’re not fans of plastic inspection hatches in splash wells and plastic deck hatches for this very reason.
But far from a leaky hatch being the only way to sink at sea. We've identified more than a dozen high risks things to look out for on your boat in this article. The following causes of sinking exclude the obvious running aground, poor navigation, forgot the bungs and rolled at the river bar.
Remember, the smaller the boat, the greater the risk of it sinking, because a small boat requires less water ingress over a shorter period of time to adversely affect its stability.
Trailerable sportfishers with live-bait tanks, in-floor fish wells, lots of inbuilt storage recesses and plumbing require extra diligence to ensure you stay safe while chasing big fish a long way from home.
In the interests of boating safety — and ensuring there are plenty of you around to read these articles in future — here are 15 key areas to check before you next put to sea on that long-range fishing trip for, say, broadbill swordfish off the East Coast of Tasmania...
1. Split or Breached Hull: A 4.8m aluminium runabout that this author once loved to death was the subject of repeated leaking due to a split hull. The hull split because it was 2mm sheet and flexing along the keel line from a lack of structural support. Thankfully, boats of this sizes tend to run thicker sheet and be better reinforced these days. But a split hull is an obvious risk to sinking. Ensure your boats is built for the task, that your trailer has proper keel supports or skids, and do check your hull for cracking from time to time. Always examine the cause of any water ingress if you are someone who runs hard at sea. Alloy hulls can crack from fatigue and flexing.
2. Busted Anchor Well Hose: While bigger boats have collision bulkheads and their anchor wells are usually separate watertight holds in the hull, smaller boats often run a simple drain tube from the anchor well to a bow skin fitting. If this tube is broken and the skin fitting is reasonably close to the waterline then you can drive water into the boat as you charge offshore. Boats have filled up this way. Check the anchor locker and its plumbing tube to ensure they are watertight.
3. Leaking Screw-On Hatches: This is a bit of personal crusade and every time I see a screw-off or spin-out plastic hatch in an engine well for bilge access I shudder. Not only do the hatches leak water over time, but if you need to access the bilge at sea then you are creating an aperture in the engine well when you remove the said hatch. With waves crashing over the back of your boat, this is fraught with danger. Plenty of boats have sunk due to screw-off hatches in inappropriate places. Even operators of survey boats with aluminium or stainless-steel or bronze screw-on hatches can find it nigh impossible to remove them over time due to corrosion. Inspect the hatches often, keep the threads clean and carry spares. Make sure you can easily remove the hatch to access what's behind it, eg, a failing bilge pump!
4. Deck Hatches: A self-draining hull with plastic floor hatches is high risk. Over time, plastic floor hatches tend to warp from people standing on them. When the deck is awash with water, especially if your self-draining hull leaks at rest with angler weight at the transom, these hatches can leak water into the bilge or in hidden areas under the deck. Experts have run tests and written about 40 litres per hour being not uncommon. If the bilge pump doesn’t work or can’t keep up, and the scuppers haven't bellows and drop below the waterline, you could be going down. co*ckpit floor hatches that don’t have large plumbing channels surrounding their openings are also high risk. Game boats backing up hard and filling the co*ckpit can soon sink if they’re also filling their lazarette and, if it’s not watertight, their engine room at the same time. An engine-driven bilge pump is a good idea for a big open-ocean boat.
5. Leaking Skin Fitting: Cheap plastic skin fittings are always a concern but especially where they are used below or near the waterline. A serious or solid knock and the cheaper plastic fittings can sheer or crack, in effect compromising your boat’s seaworthiness. Traditionally, the best skin fittings are stainless steel or bronze, with seaco*cks or ball valves below the waterline so you can easily shut them closed. The old screw-down gate valves are less reliable. In recent times, boat builders and cruising yachties have embraced the exceptional plastic Marelon seaco*ck range, made by Forespa using glass-reinforced DuPont Zytel material, since they don’t corrode and seize.
6. Dodgy Seaco*cks and Plumbing: While having seaco*cks or ball valves is essential on all skin fittings and water intakes below the waterline, these aren’t immune to maintenance. Over time, their lack of use will result in the fittings corroding and/or seizing. Ensure you keep your seaco*cks moving easily by regularly opening and closing them. Take a leaf out of racing yachties’ books and swing timber bungs on strings next to each seaco*ck for quick emergency sealing in the event of a busted plumbing pipe or hose and stuck seaco*ck. Carry spare plumbing fittings. Hose clips can cut through pipe and become points of leakage over time.
7. Leaking Live Well: Unfortunately, plenty of live wells leak. Sometimes the upper inside edge of the tank leaks because it hasn’t been properly sealed around the rim after it was dropped into the deck. A lot of the time, the hoses leak, whether from the pump or the scoop pickup. Sometimes, water just splashes out the lid and back inside your boat, filling the bilge and/or splashing salt on the batteries. A good live well is a self-contained tank that doesn’t leak and which has seaco*cks or shutoffs on all its raw-water pick-ups.
8. Leaking Fish Box: Underfloor flooded kill tanks are handy but you really need to make sure they are watertight. The hose that drains them back to the transom and the plastic bung fittings are notorious leakers, especially if they are pop-rivetted. We’ve seen examples of slack boat building where an unfilled screw hole on a sub-floor fishbox below a bung fitting (guess it was from a wayward drill bit) leaked water into the hull. The boat stayed afloat only because the bilge pump emptied the 20 or 30 litres whenever the float switch kicked in. Check that all plumbing fittings for fish boxes are watertight. Also check that macerator and Gulper pumps for fishboxes (and toilets and showers) can be accessed and isolated.
9. Dodgy Bilge Pump: Bilge pumps are designed to be reliable and near-continuous-duty pumps on your boat but they are not immune to failure. Over time, many bilge pumps give up the ghost. Boat builders we know have run a range of brands continuously in their sheds to find out which ones are best and some top brands have failed after a relatively short time, they’ve lamented. The key to ensuring your life-saving bilge pump works to its optimum is to have more than one (a backup) fitted and to ensure there is plenty of battery power. Access your bilge routinely, remove the pump from its housing, and clean its pick-up and blades from debris, fishing line and scum. Contacts, connections and wiring are ongoing issues in wet areas.
10. Stuck Float Switch. The automatic float switch on your bilge pumps is a godsend, but it’s not to be relied upon. It doesn’t take long for fishing line, engine gunk and soap scum to foul the float. That’s why it’s essential you also have a separate circuit so you can manually switch on and off your bilge pump. The switch needs to be near the dash or helm. You should also consider installing a high-water alarm if your boat hasn't got one.
11. Leaking Shaft Seals and Bellows: The dripless shaft seal is designed to keep the water out and it does a mighty fine job in most shaft-driven boats today. But it’s not immune to working loose and leaking and when the carbon seal on the retaining disk does give way it can create a minor flood. Inspect your shaft seals often, especially after periods of heavy running or suspected kissing of a sandbank in skinny water. Similarly, the bellows for sterndrives can crack over time and leak water back into your boat. Inspect and replace annually as part of your strict maintenance schedule for sterndrive-equipped boats. Not-negotiable for boats kept in the water. See our expert tips in Boating Advice: Sterndrive Maintenance by The Surveyor.
12. Leaking Sea Strainer: There are good and bad things about sea strainers with clear inspection ports. The good side is that you can see weed and debris in your strainer. The bad side is that the inspection covers screwed down in place by nuts can leak. The rubber seal beneath them can leak and the acrylic inspection window can crack if you over-tighten the threads, drop a spanner on them or there’s a sudden trauma for some other reason (they also melt in a fire). Of course, the strainer has a seaco*ck or ball valve to stop water ingress. This has to be working as we mentioned above under “seaco*cks”. That being the case, you can shut off the water, unscrew the nuts and remove and replace the acrylic inspection ports and rubber seals pretty easily. The key is to make sure you carry spares. You don’t want a leaking strainer on an engine intake with a seized ball valve a long way from home. That will sink you.
13. Flat Battery: Bilge bumps need batteries and they drain plenty of power over time, doubly so if your boat is left unattended and off shore power and it’s pumping water from the bilge every hour or so. Just make sure that your batteries are in optimal health to ensure your bilge pumps get plenty of juice. A flat battery means no bilge pump. Simple as that. On moored boats consider rigging-up a trickle charger for your batteries using a solar panel. On trailerboats with heaps of gear, ensure you have battery management system and, at the very least, separate house and engine-start batteries.
14. Bad Bilge Access: It’s absolutely critical that you get clear access to your bilges and all the pumps in your boat’s separate water-retaining and collecting compartments. You might need to get in there fast. You might also need to manually bail your boat. Some boatbuilders working to CE standards include a manual hand pump. But we also like to see a large bilge area rather than a small hole between moulded deck and hull liners. We like to get into our bilges and access the pumps easily. Before putting to sea, make sure you have a range of bailers that can scoop water from your bilge. It's a good rule to always leave port or the ramp with a dry bilge. This way you will know if you are leaking; it could be a skin fitting, a raw-water pump, an engine-driven pump, an exhaust elbow... track it down if you see water in the bilge.
15. Self-Draining Hull: Self-draining hulls are brilliant, but if the scuppers are too low they can start reverse-siphoning and your boat becomes a self-fulfilling prophecy and sinker. The key is to ensure the scuppers are clear so they drain water and rain away, and that they have a bellows system or flaps to prevent radical ingress of water. A boat sunk not long ago in Sydney due to a simple plastic deck drain
fitting around a floor hatch breaking and water emptying into the lazarette where the bilge pump wasn't registering. Leaking deck hatches and faulty bilge pumps are a dangerous combination. Another thing, quite a lot of 'sinkers' on moorings have been caused by boats with sub-floor frames that haven't got pintle or drain holes to the bilge. So each square frame area holds water and when they all do that the transom level drops and more water comes in and then... glug glug glug. Mr Boat Builder, ensure your boat's sub-floor areas drain to a bilge please.
TAKE AWAY POINT: Remember, if water is leaking into or accumulating in your hull and it’s not getting out then you’re in danger. Consider all the above points, maintain your fittings and fixtures, and adopt a dry-bilge strategy. Then you can sleep easy, set the alarm and fish wide with confidence, even in a trailerboat. The take-away message here is: check ALL your boat's fittings as part of your pre-season and ongoing offshore-boating maintenance program.
Photo credit: Some of the above photos were taken by Sydney Harbour Marine during salvage work.
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