Green boating. Is it a realistic possibility?

According to the RYA’s Sustainability Strategy published in June 2020, the two most significant global environmental issues of the moment are climate change and biodiversity loss.

The report includes numerous actions that the RYA feels can be achieved cheaply and easily by boat owners and watersports participants throughout the UK in order to lessen any detrimental effects to the marine environment.

In general, sailing yachts produce a fraction of the emissions of a motorboat, however sailors of both power and sailing vessels are generally more aware of marine pollution issues than non-boat owners and can usually be trusted to do their best if presented with helpful guidance.

Clearly, a lot of necessary behavioural changes and logistical challenges will need to be inspired, instigated and possibly financed by governmental bodies such as the Maritime and Coastguard Agency, along with other relevant authorities such as the RYA (leisure) and British Marine (commercial).

But there are also plenty of simple actions us sailors and boat owners can do to assist them towards achieving their green ambitions.

Green boating: waste disposal

Some of the worst pollutants created and disposed of by boaters are sewage, oily bilge water, grey water containing cleaning products and plastic food packaging.

A little more care and investment in the disposal of these items will make the world of difference to the environment in which we like to sail.

Toilet waste

Pumping raw sewage into the sea has long been considered unacceptable, although particularly frowned upon mainly in rivers, marinas and anchorages rather than open tidal waters.

Nowadays, some effective method of containing your black waste on board, such as a holding tank, really is a must.

Though actually only a legal requirement on new craft since 2016, it is the duty of any responsible sailor to equip their boat with sewage containment facilities – even small craft, where a simple portable cassette-style toilet will usually suffice.

Although there are currently large swathes of coastline without any pump-out facilities, those that do exist can be found at www.thegreenblue.org.uk.

Adjusting your cruising plans to suit might be worthwhile and should soon become as natural as stopping for provisions and fuel.

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Discharging your holding tank at sea remains legal in UK waters, although you’re asked not to do it within 3 miles of the coast or near Marine Protected Areas (MPAs).

Other countries are much stricter, especially in the Mediterranean, and I fully expect the British government to introduce stricter regulations in the near future too.

Composting toilets are becoming more popular with inland waterway users as well, but few are compatible with the motion experienced at sea, and disposal ashore can often be more complicated than simply pumping out a holding tank.

Grey water

Similar care should also be taken when disposing of grey water (the kind used when having a shower or doing the washing up in the sink).

Although fitting a grey water tank can be an unnecessary faff in a small craft, it’s easy these days to ensure any washing and cleaning products being drained overboard are of the environmentally friendly types.

Definitely avoid any cleaning products containing chlorine, bleach, phosphates or microplastics (polyethylene).

Once again, there are already areas in the Med that will fine boat owners should any detergent bubbles be seen trailing from their boat in a harbour or anchorage.

Bilge water

Particular care should be taken with this kind of water.

If you have an inboard marine diesel engine or petrol engine there are bound to be a few leaks or spillages into the bilge so ensure you have a deep drip tray under the engine.

Oily bilge water should either be filtered before pumping it overboard or preferably pumped into a separate tank or sealable container for disposal ashore, rather than risk it going into the surrounding sea untreated.

In the event of an emergency, emptying the bilges as quickly as possible is a must, although a leaking boat will be letting in clean seawater from the outside, simply recirculated by the bilge pump.

Outboards frequently pollute marinas and harbours, either by poor refuelling methods or leaks of oil and petrol from the engine direct.

These can be overcome by refuelling ashore (if detachable or separate tank) or by devising a means to pump the fuel into the tank rather than pour it out of a fuel can.

Ensuring your inboard or outboard engine is well maintained will also help reduce fluid leaks to a bare minimum.

Food and packaging waste

One of the simplest solutions to limiting the amount of packaging you have on board is to unpack as much as you can before you head off and dispose of the packaging ashore, keeping the food in reusable containers or lockers on board.

If you can’t do that then at least remove any packing from foods before passing them up into the cockpit, where the wind will quickly blow empty wrappers overboard.

While most foodstuffs thrown overboard will be eaten by fish, there are some items, such as orange peel, that take a very long time to degrade so should be taken home and composted.

Green boating: auxiliary propulsion

Time to ditch the smelly old diesel and turn your boat into a fully electric yacht?

Along with motor vehicles, boats of all kinds will shortly be forced to change from using fossil-fuelled auxiliary engines to zero-emission propulsion systems such as HVO (hydrotreated vegetable oil) or hydrogen Internal Combustion Engines (ICE) or electric motors.

The former is the simplest to do as most marine diesels are already able to run on HVO fuel with little or no conversion work.

But the fuel is scarce, expensive and will not be sustainable into the future.

Besides, any ICE still requires lubrication, which is another opportunity for pollution, and they remain noisy and smelly whatever fuel you use.

Meanwhile, it is already possibly to propel a sailing yacht at half hull speed in relatively calm waters using an electric motor and a large battery bank.

Furthermore, the production of clean electricity for use on board has been seriously aided by the ever-improving solar photovoltaic products now available to boat owners.

All electric yachts are still in the early stages of development and currently suffer similar difficulties to those currently being experienced in the auto industry, mainly limited range and high initial costs.

The situation is rapidly evolving, however, as more time and effort is directed towards improving batteries, PV cells and regeneration systems.

Five years from now the cost of conversion to electric propulsion will likely be similar, or even less than a replacement marine diesel ICE.

Solar power has come on in leaps and bounds over the past few years and is now significantly less expensive and more efficient, although the number of sunny days is fairly limited in UK waters, meaning you would still need to cover almost every free flat deck surface with PV panels to survive when cruising totally off-grid.

The recent availability of low-cost lithium (LiFePO4) batteries and their inherently safer characteristics (compared to other Li-ion chemistries) has also greatly aided the introduction of the grid-free boat, although the technology is reasonably complex and usually needs at least some help from a professionally qualified installer.

That said, it won’t be long before a genuine ‘drop-in’ lithium battery replacement will be available for the DIY installer (many currently available drop-ins aren’t really that simple and can even be dangerous if incorrectly set up), which should make changing over simpler and cheaper.

One major headache for boat owners– time and money spent on engine maintenance – should also be considerably reduced by converting to electric as there are so few moving parts to wear or fail.

Battery capacity and recharge/generation will obviously be paramount, but careful planning, good system design and technological innovation will undoubtedly overcome most obstacles.

Apart from battery maintenance concerns, the only other foreseeable problem might be with the motor cooling system (essential for maximum efficiency), as these will be subject to the same concerns that ICEs suffer, such as blockages, faulty pumps and corrosion.

Gas: cooking and heating

The risk involved in storing and using LPG on board a boat has long been debated.

As well as the potential explosion hazard, burning gas for cooking or heating produces almost as much unwanted CO2 as running a petrol engine.

The simple answer would appear to be to convert to electric, but electric heating is way less efficient and often totally impractical on a small boat.

That said, an electric propulsion motor will need cooling with water when running, so there is an opportunity to use that waste heat by storing it in an insulated tank, just as you can today with indirectly cooled ICEs.

Once again, as large capacity lithium-based battery banks and more efficient solar panels continue to be developed, more and more boat owners are finding they can just about provide enough power to run an induction plate or microwave for short periods, without totally flattening their batteries or running their engines or generators.

We might not be quite there yet, but by 2050 I’m confident battery and power generation technology will have developed so much further that we’ll look back and wonder why folk even considered carrying gas or fuel on board.

Antifoul coatings

Most conventional, ‘off the shelf’ antifoul coatings are designed to be toxic to marine life and if you take out all the harmful VOCs, biocides and metals you’re left with, well, paint!

As a result of current efforts at cleaning up this aspect of boating, boat owners are experiencing a gradual decrease in the effectiveness of antifoul products compared with a decade or two ago.

Already, marinas and boat yards are under strict rules to ensure any run-off water that might contain antifouling deposits are collected into a designated waste tank when they hose down boat hulls.

How long before boat owners are banned from scraping their hulls or applying new antifoul on the hard? Pretty much imminent, I feel.

Despite the admirable DIY Safe Antifouling initiative promoted by the British Coatings, The Green Blue and the Yacht Harbour Association (YHA), I foresee a time (quite soon) when all ‘self-eroding’ types of antifouling will be banned for the quantity of polluting copper and zinc deposits they leach off to settle on the seabed, thereby forcing owners to have their hulls treated professionally with ‘regulated and approved’ products only.

Copper-impregnated epoxy coatings such as Coppercoat, might be acceptable for a while longer, but I confidently predict even they will be gone before the next decade is out, and anything containing biocides of any sort will be a definite no-no.

So, what will we be left with?

Moves towards silicone-impregnated coatings that rely on making your hull so slippery that nothing can stick to it, have proven slow to develop successfully and, despite being more eco-friendly, even they are struggling to comply with the strict new regulations being constantly introduced.

They are also too expensive currently for the leisure marine industry and not very effective on slow-moving vessels such as sailing yachts.

More recently, polymer-based, ‘microtopology’ coatings have been developed.

Based more around natural surface repulsion technology, they are non-toxic and are intended to make the surface physically untenable for crustaceans and other biofoulings.

The product is said to deliver a ‘biomimetic microtextured surface’ (knobbly or ridged to you and me), encouraging the formation of tiny air pockets that aquatic organisms find very hard to cling onto.

A secondary benefit is that their superhydrophobic properties also reduce surface friction, thereby reducing the energy needed to drive the hull through the water.

The efficacy of these ‘nanotech’ products has yet to be proven beyond the lab but, provided they are shown to work, can be applied easily and their price is within the budget of the average leisure sailor, these might just provide a workable and biofriendly option for the future.

I suspect however, they’ll require professional application so won’t be popular with DIY leisure boaters.

There have been numerous brands of ultra-sonic devices marketed over the past decade and most appear to function, though with varying degrees of success.

Many have yet to prove themselves effective in a wide diversity of marine environments and all require a coat or two of hard antifouling
as well, which, in my opinion, somewhat defeats the object.

They also consume power continuously, which is a serious drawback for boat owners who have a mooring without shore power and no effective solar power.

Maybe, if we’re still making new GRP boats in 2050, somebody will have invented a new resin impregnated with some form of marine organism repellent, or an annual super-slippery, peel-off biodegradable film.

Alternatively we might just decide to ditch antifouling products altogether and simply rely on lifting our boats out every month for a quick hose-down and buff up.

Useful green boating websites

RYA www.rya.org.uk

British Marine www.britishmarine.co.uk

The Green Blue www.thegreenblue.org.uk

British Coatings www.coatings.org.uk

The Yacht Harbour Association www.tyha.co.uk

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