Experience with fouling release systems

This article actually talks about coatings that protect not only ships bottoms from fouling, but everything outside, from facades and terraces to garden devices. If you are not a sailor, this can also be interesting. The good thing is that the boat’s bottom is about the most potential place to let foul grow on, and it is the most important place to keep flat, smooth and clean. So it is the ideal thing to test if you can keep a surface clean, such as your terrace, your wooden garden chairs or the walls of your house.

So here you find the test results on the Ya.

History and future

For thousand years, as long as sailboats exist, we had foul on our bottoms and we scraped it off. Then the so called anti fouling paint came. You paint it under your boat once a year, in about 3-4 hours. It costs you for a 10 meter boat about 200 or 300 Euro, and if you let someone do it, about 400 Euro. This is a soaping paint, that contains biocides.

What is a biocide? Well, bio means life, cide means kill. It leaves that many killing components in the water. So the living creatures get poisoned, such as plants, barnicles, algues, it kills water plants and leaves the fishes with misforms and makes them die. 

The anti foulings build up in the water and this is worse and worse for nature. So the regulations get stronger. In the meanwhile the stuff is so weak that it works poorly. And still it leaves biocides to the nature. So there is no future for this sort.

It also costs pretty much money to get it off. Only a professional is allowed to spray it off with a pressure water hose, and all this water must be caught in a special sewer, to prevent this biocide would go into a sewer or in nature.

So more and more it is time for alternatives, the fouling release systems. These coatings are made so flat, that foulings can hardly grow on it. And if so, they should easily be cleaned off the surface.

Neosil and Biocoat

Under the Ya two fouling release systems have been put:

Neosil is a coating that only a professional can spray on your boat. First a special primer is sprayed and then the topcoat, that consists of a very smooth layer, probably with silicon and/or Teflon in it. That stuff makes it hard for the foul to grow and stick on.

Neosil is sprayed on the grey primer here.

Biocoat is a nanotech product, so extremely thin, that the surface should be really smooth in the first place. Here one also must know how to use the system. In contrary of Neosil, Bionics can be easily used on other stuff, like wood, or stone. (such as your garden wall). The fouling can not stick on it, because the coating structure itself is too dense, as hard as steel, and very flat.

Cleaning restrictions

Neosil and Biocoat can not be cleaned with a high pressure water syringe. It would damage the coat. But further, the coatings are strong. Compare it with steel. Don’t use steel, stone, nor sanding paper or sanding (steel)wool. Do use plastic scrapers, plastic brushes, whatever.

Biocoat also doesn’t like stronger acids.

Cleaning a 3 months fouling from the bottom

Here we show pictures of the cleaning from the Biocoat system. Actually we did not notice much difference with cleaning the Neosil, so the cleaning work on both systems are the same.

The foul grows wherever there is sunlight. So on the bows, standing vertical in the water, the fouling is well represented and tougher to get off.
On the bottom astern, where the sun hardly shines, there is hardly any fouling; you just see some yellow-grey dots.
A 3 month fouling is easy to get off. This broom wide part costs one minute work.
On the aft ship it was even easier. The left side on the picture was done in two minutes.

The complete bottom we cleaned in about an hour.

Cleaning the bottom after 10 months

We left the Ya in the water from September to July. We had a spring with great weather and lots of sun. So that helped the foul to grow. The sun came in especially on the foreship on the port side.

Here again, we show pictures of cleaning it from the Biocoat system, but cleaning it from Neosil is actually the same.

On port and starboard the fouling has grown heavily and it turned he bottom green black.
The white spots show some forming of barnacles. This was easy to scrape off (what we already did on the right).
First we started scraping with a plastic window scraper. Sometimes we sharpened it with a rough sanding paper on a plank. That helped. It takes 1 ½ manhour.
 Then we scrubbed it with a hard haired broom. This costs about 2 manhours work.
The top 15 cm we cleaned with a cloth to get the red colour back. That takes about an hour. Or more, if you want to clean it deeper to the bottom.
Although Inge was not happy with this result, I found the bottom flat enough. This picture shows the worst side, the port foreship, because there the sun ‘baked’ on it for 10 months and helped the fouling growing strong on the skin.
The more to the aft en the lower on the bottom, the less fouling and the easier it was to brush off.

Conclusion : the flatter, the better

Starting with a remarkable note: on the aft under the ship the Ya has a stainless steel heat exchanger. There the fouling was really easy to get off. Why? I think because the stainless steel is really flat. The Dijkstra’s are great sprayers and always deliver first class painting work, but however, a peace of polished stainless steel is simply smoother than paint.

Therefore, it perhaps could help if you first sand or even polish the paint before you put the Biocoat on it.

For the Neosil, I think it also can help if you polish it, let’ s say once a year.

If we compare it to the current anti fouling, some notes can be made:

  • A fouling release system like Biocoat or Neosil costs you some 3000 Euros on a 10 meter ship, done by a professional. Then it lasts long, at least 10 years. An antifouling each year costs you about 50 Euros to clean it, and 400 Euros to put it on your bottom. So the fouling release system is cheaper.
  • If you take your keelboat out of the water each season, you have to spend some 2, perhaps 3 manhours to clean the fouling off. If you are in the tropics, you have to do it anyway every 2 or 3 months for an hour or more, no matter if it is antifouling or a fouling release system.
  • The ethic thing: if you stop putting antifouling under your bottom, you live sustainable, because you stop compromising the future nature for the next generations.
In the tropics it is not a bad job to scrape the bottom. It gives a nice result, and some exercise is good for your health. Or, at least, if you have a fouling release system under your ship, and not a biocide.

Hydropower and rice growing in Mondego Valley, Portugal

Over 30 years ago Inge wrote her master thesis based on fieldwork in the Mondego Valley in Portugal. In the end of the 1970’s the Portuguese government designed a project for the Mondego Valley, to get hydro energy and to regulate the water for controlled irrigation.

The agricultural reforms were an important driver for the Mondego project, but also the construction of large hydro-infrastructural works for the energy-generation.

The picture shows the project area of the Mondego Valley. Where the dams are built, the red areas show the water reservoirs. The turbines in the dams deliver electricity. The reservoirs deliver water, to be regulated to a large area around it for irrigation. This can deliver larger agricultural areas with crops with a higher yield.
The picture shows the project area of the Mondego Valley. Where the dams are built, the red areas show the water reservoirs. The turbines in the dams deliver electricity. The reservoirs deliver water, to be regulated to a large area around it for irrigation. This can deliver larger agricultural areas with crops with a higher yield.

The project aim of controlling the flooding of the area and ensuring a new source of electricity succeeded much earlier than the land reform. Two mayor hydro-powerplants were built in the Mondego valley: the Aguieira hydro power plant, located in Aguieira, started operating in 1981. Its average annual production is 193 GWh. The Raiva hydroelectric power plant (1982) generates a yearly average of 44 GWh.  All together almost 1% of the Portuguese energy consumption.

The agricultural reforms were made to be able to control to the irrigation and drainage of the area, to protect the area from the floods. Originally only rice could be grown. A controlled irrigation would make it possible to grow crops with a higher yield. This could make cultivating what agricultural soil Portugal has, more effective. Inge came in in the late ‘80s and started interviewing the farmers in Montemor-o-Velho. In 1989, the project had been delayed, which coincided with local resistance from the small farmers, and even sabotage of the works. The bigger and more entrepreneurial farmers from the association of farmers were enthusiastic about the project.

What happened in the 30 years in between the master thesis and 2020?  

Image of the Aguieira Dam
Image of the Aguieira Dam

First, we went to see how the valley developed since then. The train from Figueira da Foz to Montemor-o-Velho took us through familiar looking small-scale villages and some abandoned farms. But further inland, we saw the image of the land reform unfold.

From around Montemor-o-Velho and some 30 km to the East, the complete agricultural area in the Mondego valley is now regulated for controlled irrigation.
From around Montemor-o-Velho and some 30 km to the East, the complete agricultural area in the Mondego valley is now regulated for controlled irrigation.
Peter walking 45 minutes from the train station towards Montemor-o-Velho, crossing one of the canals of the Mondego Valley
Peter walking 45 minutes from the train station towards Montemor-o-Velho, crossing one of the canals of the Mondego Valley

For a long time, the number of land owners stayed the same. In 2008 the number of parcels they owned had halved (so the parcels on average became twice as big). Rice (60%) and corn continue to dominate, with potatoes and other vegetables. It appears that this has been a key to success: The project adapted to small sized parcels and conciliated to predominant existing crops (rice, corn). 

For the Mondego valley itself it seems to have been a success story even though it has cost lots of time and money. Estimates from 2008 on the total investment costs for about 5.500 ha (roughly 2/3 of the original project): almost 43 million Euros. And we see that the works on the adjacent rivers have suffered severe delays, much to the dismay of farmers in those regions.


Rice growing is water consuming. The University of Coimbra and the research institute MARE carry out research on how to minimize the environmental impact of this crop while keeping the yield high. During the field work in ’89 we were welcomed with words we will never forget: You come all the way from the Netherlands to study our situation while we never ever saw those professors from Coimbra, only 30 kilometers from here”. So, this is a positive change. 

On our 45 minutes’ walk from the train station to Montemor-o-Velho we walked along the endless corn fields. We then saw another potential challenge: How to grow crops without relying on large biochemical companies.

Bayer advertisement near a corn field. Is help from large-scale biochemical companies necessary for improving the yield of corn?
Is help from large-scale biochemical companies necessary for improving the yield of corn?

New developments

In recent years several groups in Portugal have protested against new mini-hydropower plants on the Mondego and other rivers. Environmental groups and other civil society organizations were able to stop two projects. In early 2016 the government decided that only four of the original seven dams will be built: the Girabolhos project on Mondego river was cancelled. Main reason for this was the incompatibility of the fish ladders built, and the broader changes they would bring, which included the expropriation of people’s houses. The construction of a fish pass in the Açude-Ponte dam in Coimbra represented the first step of the restoration process for the fish in Mondego river. It motivated further interventions in five of the smaller existing obstacles to promote successful fish passage. This is good news for sea lamprey and shad. These are gastronomic delicacies in this region and could help promoting the development of fishery, and generate incomes for local population and regional tourism activities.

In general, the organizations defend that no more dams should be built in Portugal and the cancellation of public subsidies for hydroelectric dam projects. Municipal leaders in municipalities near the dams, on the other hand, protested against the decision to reduce the number of dams, claiming that it will result in the loss of potential profits and benefits for local businesses. Also, the flooding of the valley could be controlled better by the dams, which in the light of climate change could be an important function of the dams as well. 


Writing this blog, we realized that large-scale interventions bring benefits but often have adverse effects in other fields. The large dams hold the water and yield energy. But this leads to expropriation and potentially causes malnutrition for the underlying lands, hence the need for using fertilizers. Maintaining the system of irrigation and drainage is a complex task for a rural community. The large dams hinder the passage of fish, which makes other infrastructural projects necessary. 

The approach chosen for reducing the environmental impact of rice growing looks hopeful: stay close to what happens on the land, use local knowledge and try to improve the situation together gradually.


Van de Gruiter sponsors Fossil Free Around the World

Van de Gruiter , the specialist on rigging and sailing gear for the watersport, is sponsoring the Fossil Free Around the World project. Van de Gruiter already sponsored the Sustainable Yacht project before, with the complete running rig.
Did you know that the running rig, the halyards and sheets and block and tackles on the Ya, already last for over 37.000 miles these last 6 years? This is quality, this is the sustainability that Van de Gruiter brings in.

Old and new technologies meet on the barge ‘Albatros’

Near the Frysian town Franeker, somewhere in a channel in the meadows, we moored to the ‘Albatros’, a historic motor barge built the beginning of the last century. Michel, in daily life technician on a wharf, is the owner and captain of this strong old cargo ship. He uses the Albatros is for leisure, inviting friends, for activities around the Water scouting.

Michel Loois and his daughter before the deckhouse of the Albatros. The Albatros is called a ‘luxurious motor ship”. Luxurious, because I was built with a deckhouse on the aft, where the complete skippers family lived in.
The crane of the Albatros is also an excellent swingset for Michels daughter and her friends.

Preserving the history

Michel revised the beautiful old original 3 cylinder Kromhout diesel engine. Every mechanic who sees, hears and feels these pistons slowly, smoothly and steady going up and down, would give a deep sight of sheer luck.

I asked Michel if he enjoys it all. But he answered: “Well, to be honest, since I have no cargo, the ship is too light for this big engine. It simply can not do the work what it is built for. Only in stationary I already make enough speed. And, I nearly always make short distances, sometimes only 5 or 10 miles. This all is bad for this beautiful engine.”
Indeed, it is a pity to only run an engine in only the lowest rotations. It is inefficient, it wears the engine and the fumes contain a lot of fine dust, with extra NOx and SOx. All bad our health, for nature, and bad for the next generations.

Sailing sustainably

Michel solved the problem sustainably: “I have built in an electric motor and connected it to the shaft of the propeller. Easy does it!”
This is the way to respect the history, and respect the future of the next generations. Like his daughter’s. Now he has reduced his emisssions with about 80 to 90 percent!. And by the way, it is efficient, saves money so he will get his costs back.

Seeing is bellieving

Here below you find a small film from the engine room, with the Kromhout engine, and with the electric engine in its work and running the propeller shaft.

You want to know where the Ya is now? Check here

A Parasailor on the Ya

The Ya has a Parasailor!
The Parasailor is the very solution if you want to make enough speed in an easy, comfortable way. You hoist it, unsniff it… and there you sail. Much much calmer than spinakers or genakers.
Now the Ya is able to get enough speed in light weather conditions, enough to make the Autoprops deliver electricity. This was our weak point and we solved it! Read this article if you want to know all details about the hydrogenation on the Ya.
Bruntons Propellors was willing to sponsor it, distributor Bomarine sponsored and last but not least, Van de Gruiter sponsored again with all necessary running rigging.

Vital villages: Calstock and Burdaard

On her trip through England, Ya landed in Calstock, just before the huge 19thcentury bridge over the river Tamar, some 12 miles upstream from Plymouth.

Our daily view from our berth in Calstock. The famous 19th century bridge. Sailing ships sailed under it, and the trains brought cupper and phospate over it. Calstock was blooming in that time.

The first basic necessities for sailors are available: WIFI, fresh water, electricity and… friendly people.

Because the supermarkets had disappeared from this town, volunteers during COVID set up the Local Community Shop, to provide for the basic necessities for the villagers. It opens three times a week in the former townhall. They sell the products for reasonable prices or even for free, but you can leave a donation. The restaurants, pastie shop and therapy hub are open with measures for social distancing.

The management of Calstock Boatyard opened up the wharf for local artists and small entrepreneurs. One of them is Kim, who makes sustainable soaps, with pure oils and ingredients like walnutshells and salt. These artisanal soaps leave your hands cleaner and softer than antibacterial products.

Kim shows her freshly made salt bar soaps

Visiting Calstock made us think of how vitality and sustainability are shaped in our hometown Burdaard, Ya’s first home harbor.

Some years ago, we were afraid of seeing the local supermarket disappear, but now Burdaard has two fine small supermarkets selling the best products from the region. And many other great small shops. The township and other parties organized initiatives in the field of sustainability like energy-checks for houses. Thanks to the new multifunctional centre Burdaard even has an indoor swimming pool. There is an internationally known museum of naïve painter Ruurd Wiersma.

Local entrepreneurs recently developed ‘Burdaarder Blond’. This special beer is brewed in a village nearby and its profits go back to the community. The beer even has its own website.

Burdaarder Blond proudly shows a painting of Ruurd Wiersma on the bottle.

Burdaard and Calstock, both in their own way, manage to keep the village vital. With a keen eye for what is necessary, with pride and with local products and initiatives.

PredictWind sponsors Fossil Free Around the World.

On a daily basis busy with wind and weather, PredictWind has a keen eye for climate and climate change. So we are happy that PredictWind immediately said Yes! when we asked them to sponsor the Fossil Free Around the World project with weatherforecasts, routing and advice. PredictWind is a partner we embrace.

The coming days will cross the Bay of Biscay, and then to Portugal. Click here to see where we are now

Sailing, farming, nature preservation

Philip Merricks is a sailor and a proud farmer who happens to know just about everyone meaning anything in the nature preservation in England. And in the Netherlands as well. Philip showed us around in Rye and shared his vision and contacts with us. He even found an aluminium welder for a small but necessary repair on the staysail’s boom. This remarkable farmer is also passionate about sailing. A strange combination? Philip does not think so. 

Philip Merricks on his way to take a picuture near the 'Rampion' windmilpark west of Rye
Philip on his way to take a picture near to the ‘Rampion’ windmilpark west of Rye

Ya‘s philosophy

When he first saw Ya he exclaimed right away: ‘What a remarkable boat!’ And he kept coming back to discover more details of the design and ultimately also on the philosophy behind the design.

Elmley‘s philosophy

We found out this is where the philosophies of farming, nature preservation and sailing meet: Think carefully of what you need and then take care for what you use. Philip and his team want an economically sound company. And for continuity they want to preserve the breeding waders and wildlife in their part of Sussex and Kent. They manage their farm in a sustainable way and add hospitality to it, opening it up for camping and events. This way they introduce sustainability as a way of life to their guests as well. And they love it. All winners.

Sailing, farming and nature

What Philip and Peter have in common is; use what you need. You must now your objectives (in this case: a combination of sailing, farming and substainability),and then you take some radical decisions and make it work. 

Redshank, Elmely Marshes, Kent
Redshank, Elmley Marshes, Kent

We invited Philip to sail the English Channel with us and had a great time, enjoying good food and traditional English treats like fruitcake and flapjacks. And perhaps because they sensed lots of love for the environment on the Ya, several smaller groups of dolphins accompanied the Ya for miles and miles and played around her.  Thank Ya!

Dolphin behind the rudders of the Ya between Rye and Calstock
Dolphin behind the rudders of the Ya between Rye and Calstock

The Shower Check: save money and CO2

We were in the Medemblik marina , where the Ya always gets a warm welcome. We take showers there. Everybody takes a shower there. All together some 50 to 100 showers each morning. Although the Dutch heat efficiently on gas, an average Dutch shower brings approximately 1,5 kilogram CO2 into the air. When you use coal to heat, like in the USA or China, this can be triple! We shower a lot, so here is something to reduce. Use a checklist to reduce CO2 in your showers: the Shower Check.

The Shower Check applied

Peter made a checklist on what you can do to save CO2, and money. He applied it on the showers in the marina of Medemblik. Here you see the checklist and the results.

Medemblik Marina Showers 
CO2/energy/money saversOutcome
Throughput (flow) of the spray head4,4 ltr/min
Temperature41 degrees at outlet
Heating efficiency90% (on paper)
On/off buttonyes
Automatic stop on e.g. 2 minutesyes
Short hot water linesyes
Heat recovery unit(s)no
The Shower Check for the Medemblik Marina showers

Peter put a bucket under the shower and let it run for exactly 1 minute. The Medemblik Marina showers are well adjusted. They managed to lower the flow to the minimum of 4,4 liter per minute. And still you have a nice shower. The temperature only could perhaps be lower; this saves CO2 as well. Directly after our feedback, the harbourmaster lowered it.

If you push the ON button, you shower runs for 2 minutes. Push again, and it starts again for two minutes. Luckily there is also an OFF button, when you want to stop. Many harbour showers have coin systems and then the shower simply continues, also when you are done. It runs only for the bureaucratic reason that you paid for a certain amount of time. It is a waste. Not in Medemblik. You get exactly the shower you need. This saves money and the showers are free (the coin system would only make it more expensive).

What the marina does not have is a heat recovery unit. This installation reuses the heat from your wastewater to heat to your fresh shower water. This saves a lot, but it should be built in when they rebuild the showers. This, together with some sun boilers on the roof, would easily make the showers fossil free, and cheaper on the long run. The harbour master explained that the steep roofs  do not allow to get enough sun there. The roofs must be rebuilt then

Generally, the fossil fuels used, are reduced to the minimum. It is the main prayer of the Fossil Free Around the World project: “Three things: (1)Use only what you really need, (2) use only what you really need, and (3)use only what you really need.”
The whole installation is as ecological optimized as one can with the conventional equipment. If Medemblik marina wants to save more, structural decisions have to be made.

the photo shows that the roofs of the harbouroffice in Medemblik are not suitable for sunboilers to heat the showers and reduce CO2 because they will always be partly in the shadow of a roof.
The Medemblik Marina Pekelharinghaven. Right next to the stairs are the men’s showers. Sun boilers on these roofs would be very ineffective, because they will be always partly in the shadow of a roof.

How you save CO2- money- and energy

You can use the Shower Check to reduce your own CO2 en money emissions.

First, you can minimize the flow. In stead of a big, wide spray head creating a rain shower of about 10 or 15 liter per minute, you simply buy a so called ‘sport spray head’. These do not cost much and give a pleasant flow of about 5 liter per minute.

Second, you can reduce the time of your shower. The average shower is 9 minutes. This is not necessary (and it is also not healthy for your skin, you might give that some thought).

Heating water means combusting gas, oil or coal. Medemblik Marina uses a gas combustion heater, with an efficiency of about 85%. But there are heaters that do over 90%.

If you have the money, install one or two sun boilers on your roof. Better put your money there than on a bank. And you shower fossil free!

Ya meets soulmates from Sailink

We are on our way on our Fossil Free Around the World-trip! On Ya’s first night in Rye, UK, we met Jim Duerden of Mago Merlino and Andrew Simons of Sailink.

Mago Merlino leaving Rye, Andrew Simons from Sealink on deck, Jim Duerden safely steering through the shallow water
Mago Merlino leaving Rye, Andrew Simons from Sailink on deck, Jim Duerden safely steering through the shallow water

We found out we have mutual friends: the Tres Hombres. Andrew actually works on the new project, the Ecoclipper. During a great Moroccan-style diner to which we both contributed, we discussed our plans for the future. Andrew got the briljant idea to set up a new way of connecting people and places through sailing. He found Jim, a skilled sailing instructor and one of the few to teach on Catamarans also enthusiastic for the project. What could be nicer than travelling from the north coast of France to the south coast of England by sail? They are looking for ways to have a regular schedule so it gets really easy to book for the trip as well. Check them out at www.sailink.eu!

In Rye, to our great delight, we also met with our friend Philip, who sailed with us to Calstock. We’ll tell you more in one of our next blogs.

The Ya departs

The Ya departs from the berth of the Clean Wave Foundation at Burdaard, Fryslan, Netherlands for the fossil free circumnavigation . COVID regulations forbid festivities, but the papers write about it.

Brunton’s Propellers sponsors with the Parasailor for the Autoprops

We are very glad that Brunton’s Propellers contributes to  the fossilfree world tour. Two of their Autoprops are under the ‘Ya’. These propellers are the solution, first to get the most efficient generation to the dynamos. Secondly, they are very efficient when we use them for propulsion, far better than most props. And third, when we don’t use them, they automatically go in the feathering position and  give the least resistance.

The Autoprops are extremely efficient, in propulson and generation. They make the hydrogenation work on our 34 feet sailing yacht. In light winds the Ya simply sails to slow to make any prop work, even the Autoprops. The Parasailor is big, steady an reliable sail that will solve this problem. With its special wing it is an innovation. Laurens Morel is invited to make pictures of the Ya sailing the Parasailor. We will keep you posted.