If you are having a boat/shell built for you for fitting out yourself, it would be worth considering specifying a Tek Tanks plastic water tank for your narrowboat. Once fitted, it will continue to provide clean, taste free water for many years without any maintenance other than sanitising once a year. We would be more than happy to work with your boat builder to design a plastic tank suitable for your application. A typical Tek Tanks narrowboat plastic water tank system can be seen below.

Because Tek Tanks can custom build these plastic tanks they can be made to fit the available space allowing an increase in capacity over a standard rectangular tank. The following downloads  provide useful information when preparing to sketch up your narrowboat tank.

Custom Tanks Design Guide , Quotation Request Form and Tek Tanks Standard Fittings

The material used is a 10mm thick high density polyethylene which is of food grade and is guaranteed not to taint the water. Tek Tanks can provide a huge number of fittings and are sure to have the type you are using in your water system. Tek Tanks can also supply pumps, hose, clips, deck fittings, calorifiers and much more for your water system.
Tek Tanks are also able to supply black and grey waste tanks both custom built and standard off the shelf.

Narrow Boat Water Tank Rendering

The following is an actual post on the Canal World discussion forum:

“At first I thought it was severe rust…. but its like orange/brown calcium build up of some description. Really disgusting and gross! Even when I’ve sorted it out there’s no way I’ll be drinking from the tap again (although I only ever drank the water when it was boiled first). There’s no way this can be hygienic or safe to use for drinking water???”

Narrowboat water tanks are traditionally installed in the bow of the boat and are an integral part of the structure. They are painted with a bitumen type paint, similar to that used for blacking the hull and needs to be re-painted every 3-5 years. They are filled from the foredeck via a deck filler and an inspection hatch is also positioned on the deck for access and cleaning. These integral tanks will eventually suffer from calcium and lime scale build up and will start corroding over a period of time and will inevitably look like the one in the picture.

Once they get to this stage it is a laborious job to empty, clean, dry and re-coat. Once all this has been done you will probably wish you had specified a Tek-Tank when you ordered the boat!