PBR’s Mark Featherstone and Jo Moon head for the Continent on a mission to test the latest solution to the problem caused by traditional antifouling. Could this product and service be the ‘silver bullet’ we’ve been looking for?

A few summers ago, we had a call from a friend asking if we could make use of his Goldfish RIB for the season. Between boats as we were at the time, this was a welcome blessing and we had a fabulous couple of weeks making full use of this sleek Norwegian beauty. With its powerful inboard diesel mated to its super-quick stepped hull, the RIB got up onto the plane in seconds – raw power meeting pure hydrodynamic efficiency.

All well and good – until, that was, we came back to the boat after a hiatus of a week or so, pulled away from the mooring trots and found a very different experience altogether … This once-sleek mermaid had bizarrely morphed into a 50-a-day smoker! My first thought was to check the engines, but there were no issues there. After a few days of lacklustre performance, we jumped into the water with masks to inspect the hull’s underside – only to be met by a sludge brown coating of algae all over the gelcoat. But surely this thin layer of growth couldn’t be the cause of the issue, could it?

The boat was taken out of the water, pressure-washed off, and then, hey presto, normal service was indeed resumed. I was amazed how just a little accumulation on the hull over such a short period of time could have such a drastic effect on the vessel’s performance. Of course, this is why so many of us antifoul our boats. But a slimy or weedy hull doesn’t just affect the boat’s performance, the drag incurred also means that more fuel is consumed. This in turn equates to increased cost and, of course, ultimately more CO2 emissions.

Boat wash allows cleaning of the hull in a eco-friendly way without the need for anti-foul – © iStock-Martin Wahlborg

Foul play

Hulls can gather up to 150kg of fouling per square metre in just six months. In turn, this can result in an increase in fuel consumption of up to 50%! Up until now, the main solution to this problem has largely been the application of toxic antifouling paint or the costly copper bottoming of a craft. While the extremely toxic TBT formulations have been banned for some years, the newer ones are predominantly copper oxide based and contain additional biocides that kill or incapacitate algae and smaller organisms. These are then fed on by other marine life, impacting the food chain and changing the delicate balance of our marine ecosystems. Some studies estimate that an average-sized antifouled boat leaks 0.82g/cu per day over a five-month season. This equates to a fridge-sized lump of copper being dumped in the harbour every year!

Apply of traditional anti-foul – © iStock-Wirestock

Another ‘solution’

Now, an innovative Swedish company believes that it can offer a system that is not only kinder to the environment but could also cut costs for boat owners. We met up with Carina Bjerner, CEO of Drive-in Boatwash, at their flagship centre on the west coast of France to find out more. Here is our exclusive interview:

Carina, we’re by the water in a busy marina looking at four sets of bright-yellow brushes that stretch 6 metres between two finger pontoons. Can you explain to us how the system works?

Our Drive-in Boatwash (DIB) is a hull-cleaning system for boats up to 16 metres in length. We are looking to replace toxic antifouling with a frequent hull-cleaning programme. A gate at the outer edge is lowered to allow the boat to drive in and moor up. The gate is closed and the cleaning activated with a handheld remote control unit that operates the brushes. These automatically align with the hull and move backwards and forwards along the hull to remove fouling. The brushes are mounted on a U-shaped marine-grade aluminium frame and are made from non-abrasive durable polymer. The really clever bit is that the system encapsulates the debris in a basin underneath, preventing it from entering back into the marine environment. It’s a deceptively simple concept but one that relies on high-quality design and production.

The jet wash is integrated into the system and finishes off the job nicely

The system is a Swedish design. Can you tell us more about your company and how the Drive-in Boatwash idea came about?

Our company is based in Sweden and we design, manufacture and install the systems in seven countries across three continents. Swedes have historically been early adopters of new technology, but at DIB it’s important to us that we take on board the consequences that new technology can have, and we aim to create a culture of environmental responsibility, innovation and increased enjoyment for boat owners. Our founder has a proven record in hydraulic manufacturing and is used to finding new ways to solve old problems. He started the company in 2009 when he became fed up with having to wash his boat down and antifoul every season, and the Miniwash was born. This system was moved by trailer and the contaminants that were washed off were not collected and removed, but the intrinsic design was there and led to the development of the Drive-in Boatwash we see here today. Our manufacturing pedigree informs our processes and every part is made to the highest spec – the gate system alone takes 80 man-hours to make!

Here at PBR we know how important it is to advocate initiatives that support the improvement of the environment. You mentioned that you have a culture of environmental responsibility and increased enjoyment of our boats. Can you explain how these two cultures work together?

Absolutely! We see the DIB system as part of a whole, giving boat owners the opportunity to be aware of what they can do to reduce the impact on the environment. By avoiding antifoul paint we can cut down and move towards the eradication of levels of copper in the sea. However, while we all want to work to improve the environment, we still want to enjoy our boats. Owners today want convenience, they want to step aboard and go, and they want the boat’s performance to be the best it can be and the most fuel-efficient too. After all, if you’ve got a fantastic new boat, you want to look after your asset in the best way possible.

Drive-in Boatwash, close up of brushes

Lastly, where do you see the company, and indeed antifouling, in five years’ time, and are there any plans underway to further expand? 

Europe is leading the way in regulating toxic biocide paints. In fact, in Sweden, from May 2024, the use of VC17, a classic copper-based paint, will be prohibited. We want to continue to be part of this conversation, collaborating with stakeholders on the issues that affect the marine environment and enhancing our products to facilitate easier and faster service. Our primary aim is to expand our presence across multiple markets and make the Drive-in Boatwash part of the environmental solution in a marina near you! To this end, in terms of the UK, we are already in discussion with MDL Marinas and look forward to the first installation, taking place this year.

The Boatwash is easily controlled from the pontoon

PBR’s verdict

The positives

Time saving: The 24ft yacht you see in the picture had a reasonably dirty hull, which was cleaned in just 20 minutes. The operation was smooth and efficient, and the boat owner, a regular DIB customer, was delighted with the results.

For a marina, this could be a time and money saver as lift-outs wouldn’t need to be as frequent, and washing down won’t take as long for a boat that has been regularly cleaned throughout the season, thereby increasing the number of boats that can be dealt with at that busy end-of-season time.

The Drive-in Boatwash Bigwash machine.

Money saving: No mid-season lift-outs – an annual lift-out should suffice to inspect the hull, change anodes, etc. No antifouling cost, which usually varies from £10 to £20 per metre, although this saving will be offset to some degree by the cost and number of times you use the Boatwash.

Saving on fuel: The estimated 4- to 8-knot saving on performance that a clean hull will produce will consequently save the additional fuel needed to get the boat up and maintained on the plane. For marinas there would also be less demand for expensive washdown systems.

Eco benefits: A reduction in fuel consumption will lower CO2 emissions.

Using an alternative to toxic antifoul paints improves the marine environment.

There may also be a biosecurity bonus here for harbours and marinas that are concerned about a vessel being ‘contaminated’ with potentially invasive and/or non-native species entering or leaving their waters.

Lifting out is necessary for larger craft, boat wash would negate this.

The negatives

Carina told us that initially the DIB system was installed in her local marina and the operation was left to the members, who were trained and could then use the Boatwash as required. Issues soon arose from mishandling, and having watched the operation, I can see that it does need to be manned by a fully trained operative who is able to understand how the hydraulics work and deal with issues such as the gate jamming that can happen if you don’t work with the tide. Regular maintenance is also required, and the basin needs to be vacuumed out on a regular basis. The brushes also have to be replaced every 1500–3000 cycles in normal use.

The system itself will collect biofoul and will need to be cleaned off at intervals depending on how brackish the water is; this will involve a diver – something that needs careful consideration in a busy marina and that carries its own risk.

Technical data

• The system is 8.3m wide and 18.45m long, and its draught is 3.2m.
• The DIB 16 cleans motorboats up to 16m LOA with up to a 5m beam and 0.9m draught.
• Using a three-phase power supply, a 15-minute wash will consume around 1kWh.

Antifoul dos and don’ts

• Consider more environmentally friendly paints and non-biocidal coatings.
• Avoid power spraying or doing antifoul work close to drains.
• Use portable bunding to collect heavy metal biocides.
• Use a marina with a filtered washdown system.
• Follow the ‘Protect, collect and dispose’ guidelines on the Green Blue website, which also has lots of great advice on sustainable boating practices.