Sea Fend’s new anti-sinking system uses giant air bags to keep a boat afloat even when it’s flooded
The boating world is full of clever devices to try and prevent groundings and collisions but few if any that have attempted to tackle the consequences of it. That’s about to change with the launch of a new system aimed at preventing a stricken boat from sinking. Called Sea Fend, it relies on giant airbags to keep the yacht afloat long enough for it to be motored or towed back to port.
The idea stemmed from a group of Italian boat industry executives intent on resolving the perennial problem of sinking craft – there are said to be over 3 million wrecks littering the ocean’s seabed. Leisure boats seem to be particularly prone to it due to their brittle fibreglass hulls and less experienced skippers and crews.
All it takes is a collision with a submerged rock or floating log for a previously sound boat to end up at the bottom of the sea. As well as the possible risk to life this poses, there’s also the potentially huge financial cost of recovery and/or replacement not to mention the environmental cost of fuel, oil, plastics and other chemicals leaking into the sea from the sunken hull.
Inflating the giant air bags will keep the boat afloat even when the bilges and decks are underwater
Nor does it require anything as catastrophic as a collision to sink a boat; we’ve all seen boats that have sunk on their own moorings due to failed skin fittings or ruptured hoses.
Sink or swim
On the basis that prevention is better than cure, Sea Fend’s new system aims to keep the boat afloat however bad the problem is, not by stopping water ingress but by creating enough hydrostatic lift to ensure it doesn’t sink even when flooded. It does this through a system of inflatable flotation bags that are permanently attached to or integrated into the hull’s topsides.
Once it becomes clear the hull is fatally breached, the skipper triggers the system
In the case of a new-build boat, these can be factored in at the development stage so the tightly packed bags can be tucked into specially moulded recesses behind flush-fitting panels that are all but invisible to the naked eye.
Once triggered, an electromagnetic release opens the panels, allowing the flotation bags to pop out and inflate. On a retro-fit installation, the bags are mounted externally in discreet torpedo-shaped tubes designed to minimise drag and visual interference.
It does still require careful calculations to ensure the mounting points are strong enough and the hydrostatic lift is in the right place to keep the boat stable even when the hull is filled with water, but Sea Fend will work with customers to ensure that’s the case.
The bags then take from five to 25 minutes to inflate fully, depending on the size of the boat and system – quick enough to prevent most sinkings
Being a modular system consisting of multiple separate bags rather than one big one, it can easily be scaled up or down to match the size of boat and moved around to alter the centre of balance. The current set up has been designed to suit boats from 30-65ft with a displacement of up to 45 tonnes but there’s no reason it couldn’t be expanded up or down.
On a new-build boat the system is designed to be fitted into specially moulded recesses with flush fitting panels so they aren’t visible from the outside
Giant air bags
Unlike the air bags in a car, which are triggered automatically and inflated in milliseconds by a small explosive device, Sea Fend’s flotation bags have to be triggered manually and are inflated by powerful air pumps rather than a chemical reaction or compressed gas canisters.
These are mounted inside watertight housings in the engineroom for ease of access and can be powered by multiple sources, including the boat’s own electrical system and/or a separate battery pack inside another waterproof casing to ensure it carries on working in the event of a flooded engineroom.
The control unit has an app for remote triggering and monitoring
It’s triggered either by pressing a protected helm switch for five seconds or by a specially developed smartphone app. This monitors the boat’s systems as well as the battery charge level, tube pressures, valves and GPS position so the owner can trigger the flotation bags remotely if required.
It also sends an SMS to the owner’s chosen emergency contacts with the GPS location of the boat Sea Fend is already in discussion with a number of boat builders about making it a factory fit option on new-build models and has built its own ‘sinkable-on-demand’ 7m centre console boat to demonstrate its potential.
Meanwhile, it’s offering the kits direct to existing boat owners as a retrofit item. Prices will depend on the size and installation costs of the boat but Sea Fend is expecting it to be equivalent to around 3-5% of the overall value of the boat.
On an outboard-powered boat, such as this 7m demonstration model, the engine stays above the level of the water so you should still be able to motor slowly back to shore
Verdict
Anything that improves safety at sea has got to be a good thing and there’s no doubt that Sea Fend’s new system has the potential to save lives as well as money.
It’s not hard to imagine insurance providers and commercial operators taking a keen interest. Whether leisure boat builders and buyers will see it as a worthwhile investment is harder to predict.
Nobody likes to dwell too long on the likelihood of their own boat sinking and the addition of air bags to it, however discreet, may not send out the right message to new boat buyers and their guests dreaming of relaxing days out on the water.
Then again everything from seatbelts to air bags were once frowned upon as an unnecessarily pessimistic addition to cars.
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