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Hygiene on the boat - black water, gray water ... into the water?

There is no reason not to apply hygiene rules, which one naturally obeys in the familiar home, at sea and in the inland seas.

By Michael Kunst, published on 11.10.2018

This is what awaits you in this article
  • Tips for the disposal of black and gray water.
  • Why collecting waste is so important.
  • No matter where and no matter when: We always travel to sensitive ecosystems.

"Black water, gray water ... just get into the water" It wasn't that long ago that such sayings (and the corresponding actions) still counted as a kind of "rough sailor charm": Haha, that's how they are, the sailors - somehow rude, but cordial. Today, all water sports enthusiasts who are out and about in yachts and boats on lakes and rivers know that strict hygiene rules must be adhered to, which apply across the EU and have even been tightened in some countries (e.g. Sweden).

The inland lakes, seas and coasts are to be kept as pure as possible. What has meanwhile become a matter of course for the environmentally conscious yachting enthusiast is still being ignored by a surprising number of sailors and motorboat drivers, especially on vacation trips. You're on vacation, and you don't want to bother with grandiose issues such as the ecological balance of the anchorage or the plastic littering of the oceans.

In fact, it can be observed again and again how sailors and motorboat enthusiasts make use of a special regulation - if they are caught by the authorities, it can be quite expensive, by the way.

But maybe it is also because there is simply a lack of understanding of the problem. Because what can a little bucket of child shit do in the big bay? Just!

Black water - isn't everything biodegradable?

A yacht with four people on board produces an average of 10 to 13 liters of black water per day. Black water refers to human feces and urine mixed with toilet water - i.e. the contents of the on-board toilet.

These substances are actually biodegradable: if they were led directly into the sea and not collected in black water tanks, they would in principle hardly be harmful to the environment. However, they are a bacteriological danger for people in the immediate vicinity, i.e. on the beaches of the anchor bays etc. Black water in the sea or in an inland lake can therefore promote the development of bacteria such as staphylococci, salmonella and coli bacteria, contain viruses, accelerate the growth of parasites and even drug residues in
In bathing waters or in coastal drinking water.

Furthermore, some types of algae grow faster with the “fertilizer” of black water than nature intended and thus endanger intact ecosystems.

Therefore, the following applies: Collect black water in the tanks provided for this purpose and dispose of or pump it out in the ports provided for this purpose.

Gray water - isn't it distributed in homeopathic doses?

All water that was used for rinsing and washing (including the boat) on board is called gray water. It contains chemical substances per se, as washing and rinsing without chemical additives has become unthinkable these days. Unless one pays strict attention to the biodegradability of the products used (see below) Basically, also when using «biological» agents, gray water, however clean it may seem, should also be collected on board. Because even the smallest amounts of chemical or toxic substances can seriously disturb the ecological balance in lakes and seas and are considered dangerous for fauna and flora. Even if optically "everything dissolved" that you just poured into the water.

Just pour it overboard? Do you do that at home too?

For boats and yachts built after January 1st, 2008, EU directives stipulate that every toilet installed on a ship may only be connected to a water retention or treatment system that complies with the current, Europe-wide standards. The accumulated gray and black water must not be poured overboard in ports, but must be disposed of in the black and gray water tanks provided for this purpose. This also applies to the 3 nautical mile zone at sea. However, if the on-board toilet is equipped with a shredding and disinfection system, it is possible to dispose of the treated water outside the three-mile zone at a speed of four knots directly in the sea.

Outside the 12 nautical mile zone, however, black and gray water may be discharged “untreated” directly into the sea.

Regardless of the exceptions mentioned, it is nevertheless recommended that black and gray water also be collected at sea and pumped out in the tanks provided for this purpose in the next port. This applies in particular to inland lakes: there, even the slightest "quick-draining-the-black-water" is usually a punishable offense.

There are no compromises when it comes to the disposal of chemical and dry toilet contents: they should be disposed of on land in the waste bins provided.

Biodegradable gray water

If you walk down the supermarket rows for detergents, hygiene products and cleaning agents, in addition to the almost infinite selection, it is particularly noticeable that 99 percent of the agents on offer are still not biodegradable.

Most of these products still contain highly chemical surfactants and other chemical ingredients that pollute lakes and seas and cause great damage to flora and fauna in the aquatic environment.

As an environmentally conscious water sports enthusiast, you can actually keep the gray water relatively “clean” with biodegradable agents, which are usually somewhat more expensive than “conventional” products. Look out for the corresponding ECO label or purchase suitable sea-friendly products from specialist marine dealers. In any case: Use sparingly!

Why collect waste?

The other day I could hardly believe my eyes: A family is sailing out of an anchor bay in their cruiser, where they must have just had lunch. A little further out at sea, they then simply threw the "neatly" collected rubbish such as leftover food, serviettes, plastic packaging, plastic cups and even dishes overboard. According to the motto: The sea will sort it out somehow.

It really doesn't need to be mentioned at this point that plastic is probably the greatest enemy of the “lake” or “lakes” ecosystem - the rotting time of some materials is thousands of years (see, among other things, the article “One Minute Boat”). This is why the following always applies: collect rubbish and then later separate it on land and dispose of it in appropriate waste containers. In general, it is important to say goodbye to a typical holiday laziness: Studies have shown that most holidaymakers no longer want to have anything to do with the rules they like to adhere to at home. For example, water sports enthusiasts who are otherwise environmentally conscious eat “sometimes” from plastic dishes (because washing up is so annoying) or buy food that is hidden in innumerable layers of packaging.

Consider it part of the whole

Basically: Our leisure time on the water - regardless of whether motorized or under sail - should be as hygienic and environmentally friendly as possible. Everyone has to be aware that we are always navigating a sensitive ecosystem with our yachts and boats, no matter which body of water we are on. A system that is directly related to other habitats, in which in turn people live who may not have anything “to do” with water sports, but who could be affected by certain atrocities on and in the water.

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Michael Kunstauthor

Michael miku Kunst (60) has been a sports reporter for more than 35 years. While in his younger years it was more endurance sports that lured him to the farthest corners of our planet, today it is more or less crazy sailing boats on the oceans and inland seas that fascinate him.
Among other things, miku's fleet includes a 25-year-old Laser Standard and a somewhat worn-out Mini 6.50 prototype (No. 247), with which he is on the Atlantic off Lorient.