Chlorine and silver ionization in tankwater: does it influence your health?



Freshwater treatment through chemical disinfection is often found on yachts, let’s have a deeper look into this.

Commonly used chemisterilants such as Chlorine or heavy metals (e.g. Silver- or Copper-Ions) are useful to prevent growth of any organic matter within your tanks just like it is used by most water suppliers providing large quantities of water to municipalities. Using such oxidation agents a couple of times per year followed by a thorough rinse is unproblematic and is often part of standard maintenance. Dosing systems for permanent use will keep your tanks, piping and service water clean, yet when the tank water is used without post-filtration (activated carbon) a displeasing feeling on your skin or hair can be quickly experienced after a shower. (Think about dry skin or elderly women with purple hair….)

In regards to drinking water these treatment methods are rather adverse though. While pathogens (virusbacteriumprotozoaprion, or fungus) can be simply overcome by UV or Ultra-filtration, any chemisterilants like chlorine will introduce disinfection byproducts (DBP’s) which are considered carcinogenc and are suspected to damage the liver, kidneys and central nervous system.

The concentration of DBP’s is related to the amount of Total Organic Carbon found in your raw water source which varies from port to port. So far, various types of DBPs have been identified but most research has been carried out on chlorinated disinfection due to it’s extensive use. The amount of information out there on this particular subject is shear unbelievable, yet it hasn’t found its way to common knowledge?!?

Sadly it is the same case with pesticides, pharmaceutical residues and hormones. Actually we can often read that especially pharmaceutical residues in groundwater in the Western world are of increasing concern for water service providers in their task to provide good public drinking water.


On yachts we have the advantage that we are already quite familiar with organizing our own ‘(drinking) water plant’. Most important though is that we do it the right way  to get healthy drinking water and not just ‘potable’ water.

Having the right drinking water solution on board at the point of use does not only substantially reduce our plastic waste, it also provides a healthy version of the “prime source of life”.

For more info or a quote for a sustainable and healthy drinking water solution on board, please complete the contactform below.



Workshop Water without waste: testing and tasting of drinking water on board of yachts

After a succesful presentation of our sustainable drinking water solutions at the METSTRADE in Amsterdam, we have the pleasure to invite captains, engineers, first mates and chief-stews/chefs for our very informative workshop:

Turn the Tide on Plastic PART II, Water without waste: 
testing and tasting of drinking water on board of yachts 
Friday 23 November, 17-18 hours (followed by drinks other than water ;-))
in Astilleros, Palma de Mallorca, as part of the Acrew event
The survey ‘Turn the tide on plastic, also on superyachts  done by Marja Kok clearly showed there is a huge requirement for a sustainable alternative to plastic bottled water on-board.
Marja Kok and Andreas Buhl (drinking water purification expert) teamed up as ecopreneurs in Water without waste, offering complete sustainable solutions for healthy drinking water. In this workshop you can educate yourself about commonly found contamination in water sources (tap and tank water versus bottled water) and what a sustainable solution on a yacht looks like.
We will go deeper into the convenience of having purified, chilled and even sparkling water directly from your tap. Explore installation and space requirements, maintenance efforts, total costs and overall savings compared to plastic bottled water.
During the entire Acrew event, you can refresh yourself with water without waste provided by a Water without waste demonstration unit (bring your reusable bottle or buy one at the event).
Superyachtradio will live broadcast the event.
Places for this workshop are limited, so please Sign up

November reflections…

Stormy days and nights in the Med keep yachtcrews busy, either in preparation for their Ocean crossing either while ‘just’ sitting on the dock. Checking the lines, being on watch, cleaning up after the storm….

When the silence is back again, it is time to enjoy a cup of coffee or tea and focus on the pre crossing- or winter works, maintenance- and refit plans and putting together estimates for the owner or management company.

Hopefully these ‘end of the year’ months will leave you some time for reflection as well, for some thoughts on the impact that you as a captain, crew member or shipyard can have on reducing plastic pollution and on saving our oceans. In case this is too far from your bed reflect on how you can make life of your owners, guests and crew healthier and life of your crew easier. Some small changes on board that can make big differences. By making the right choices you can have healthier drinking water on board, reduce your running costs and take away your crews literally ‘pain in the back’ of continuously provisioning, storing of bottled water and disposal of the plastic waste at places where recycling often is no or a bad option.

We look forward to feed your thoughts and knowledge about sustainable drinking water solutions and share your and our reflections about the impact the nautical industry can make. Looking forward to welcome you at stand 07.332 at the METSTRADE in RAI Amsterdam from 13-15 november or at the Acrew event in Astilleros in Palma de Mallorca from 21-23 November.



Sustainable crew award

What an unexpected honour, I am nominated and voted for as one of the 3 finalists for the Acrew sustainable crew award.

It surely feels as a reward for all the energy that I used during the last year to create awareness among my fellow yachties for the quantities of single use plastic we are using. Especially plastic bottled water on board of yachts leaves an enormous unnecessary amount of plastic waste. My survey ‘Turn the tide on plastic, also on superyachts’ and the results got quite some attention in the nautical press and made captains and crew think about how to make a change and encouraged them to make the transition to water without waste.

The teaming up of Water without waste with Andreas Buhl, water filtration and purification expert/developer and general manager of a Dutch technical company has brought the activities of Water without waste to a next stage. We offer, deliver and (optionally) install complete sustainable and measurable drinkingwater purification systems as well as reusable branded/personalized drinking bottles.

On Saturday the 13th of October, the Acrew award gala will take place in Le Palace in Nice. A glamorous event for captains and crew with cocktails, dinner and party.


As one of the finalists I want to share this event with those who showed their interest for water without waste, for example by participating in the survey or (showing interest in) making the transition from plastic plastic bottled water to water without waste. If you are interested to join this event, please get in touch with me via email or the contactform on the website and receive a free entrance ticket (value € 150). Free tickets are limited, so don’t wait long.

Looking forward to see you in Nice!

Marja Kok

More info about the event, can be found here Acrew International crew awards

From plastic bottles to water without waste: do it the right way!


Water without Waste (WwW) proudly recognizes a fast growing interest in water treatment solutions for yachts since its Survey ‘Turn the tide on plastic, also on superyachts’ about plastic bottled water consumption within our industry. Relevant press published diverse articles and lively discussions on online platforms show different opinions and experiences.

It is in our utmost interest to provide captains, crew and owners with information and to create awareness on technologies which can be trusted and which treatment solutions are of limited or no value for the yachting industry, respectively are riding the market opportunity.

To explain it in simple wordings: yachts, taking raw water from different sources and thus of different quality, and storing it in tanks and pipes (of different materials and condition) where the water is sitting at for bacterial growth favorable temperatures, have different filtration/purification needs than a house/office with potable water from a running tap.

Only complete, reliable and measurable solutions can create the necessary trust to turn the tide on plastic. Any technology that is not 100 % trustworty or a half solution, will lead back to plastic bottled water and that is undoubtedly our worst scenario.

Therefore it is important to identify the commonly found pollutants and to understand the difference between potable water and drinking water.

Any inline cartridge filtration (downstream the watertanks) coming in a range from micron to ultra filtration, activated carbon and magic filters are sufficient to enjoy transparent, odor and taste less fresh water under your shower. However, to have truly healthy and tasty drinking water, treatment solutions downstream the watertanks below Nano membrane technology are not recommended since they don’t take care of carcinogenic DBPs (disinfection byproducts for example after chlorination of water in the tanks), pharmaceutical residues, pesticides, herbicides, heavy metals and micro plastics.

In other words and as an easy check of your actual system or your foreseen system, filtration/purification methods downstream the watertanks that discharge water, function on the level of membrane technology and are either nano (the most sustainable since the discharge of water is the least possible) or low RO (with a higher discharge of water). If there is no discharge of water, the level of filtration/purification is less and doesn’t exceed the level of ultra filtration.

Solutions that match the above recommendation can also come with monitoring equipment to guarantee best water quality and indicate maintenance requirements. Raw water qualities are changing with every tank filling and therefore make producers replacement recommendations of limited value.

Additional hardware such as cooler/carbonator devices and capacity to provide required volumes as well as easy to clean, attractive reusable bottles complete the convenience, another cornerstone to turn the tide on plastic and to fit superyacht standards.

Please continue the road to plastic bottle free superyachting and provide water without waste, but do it the right way

For an assessment on your yacht or a proposal to get healthy and sustainable drinking water on board, feel free to get in touch.


How is your mind set?


Do you think we need plastic bottled water to hydrate ourselves?

Do you think that by not throwing plastic bottles in the sea, but in the ‘recycle’ bin you are doing perfectly fine?

Do you think it is not possible to have perfect drinking water on board by filtration, purification and cooling?

Do you think plastic in the ocean is something the animals in the sea as well as ourselves should get used to?

Is plastic bottled water still being drank on board of your yacht?

In case your answer to one or more of the questions above is YES,  please read the article Mindset Shift by Michael Howorth, published on page 40 and 41 of the July 2018 issue of The Telegraph, a publication of Nautilus International.



The Superyacht Cup Palma: who is competing with whom?

From 20-23 June, 18 of the most beautiful sailing superyachts raced against each other in the bay of Palma in great circumstances. Instead of, like in the past, sailing on one of these beauties, I have chosen this time not to compete with my fellow sailors but to fight against the biggest monster threatening our oceans, called ‘plastic’.

The Superyacht Cup joined the Clean Regatta program of ‘Sailors for the sea’, in fact world’s only sustainability certification for water-based events. By this the SYC made a commitment to reduce the environmental impact as much as possible. Main target was to have the yachts sail plastic bottle free. For this a shore filtered drinking water refill station was available as well as free reusable bottles sponsored by Southern Spars were provided.

Imagine how many small plastic bottles of water become disposed at regattas! It is difficult to understand why still so many of these technically advanced yachts need a shore refill water station to have healthy, tasty and environmental friendly drinking water on board. Has it been a blind spot in the building or running process of yachts to forget to install filtration/purification/cooling equipment of drinkwater? Or has plastic developed so quickly from a useful product to an (ocean)life threatening monster of which the nautical industry slowly becomes aware of?

Although not all yachts complied (completely) to the request to sail plastic bottle free, there absolutely could be noticed a huge reduction of single use plastic used during and after the races and an increased awareness about this subject.







Water without waste (WWW) was present:

1. to help to create awareness and willingness among the yachties to comply to the Clean Regatta program and to practically assist at the SYC water refill station and distributing the reusable bottles:

2. to encourage yachts to go for a permanent nautical drinkwater filtration/purification/distribution solution on their yachts to sail plastic bottle free all year round. No provisioning, storing, cooling and garbage disposal of huge amounts of bottles anymore which is not of these times. It was promising to see that quite some captains showed their interest and will join (the Action plan of) WWW to come to water without waste on their yachts.

Every small step makes a big difference. May many yachts and regattas follow in our wake!


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