We have a Bavaria 34 which we took delivery of from Opal marine Christmas 2001. I did not like the small rectangular holding tank on offer as it was too small and obstructed the very good space in the forward end of the starboard cockpit locker.
My solution was to construct my own fiberglass tank which i have fitted in the space forward of the fuel tank, below the base board in the starboard cockpit locker.
The tank was simple to construct by first making a wooden plug to the shape of the space available. This was faired off and used as a male mould, the fiberglass being built up on the outside of the plug. The top was formed seperately and screwed on with a gasket so that it can be removed if ever the need arrises. (hope it never does).
We have more than twice the capacity of the Opal tank at approx 40/50 litres.
When we ordered the boat we had Opal fit an extra skin fitting and valve under the weashbasin in the heads in anticipation of fitting a holding tank at a later date. We have fitted a two way valve on the toilet outlet and all the necessary pipework so that waste can be diverted from sea outlet to holding tank. We did not fit any facility for pumping out from the deck. We can only discharge the tank at sea. This is done by opening the valve at the additional outlet and pumping the hand operated Whale pump which i have mounted on the bulkhead at the forward end of the starboard cockpit locker. All the fittings to attach the pipework to my home built tank were purchased from my local chandeler and it took about a day to install. the tank was built over a period of about two weeks.

My total cost was about £100 and the system works a treat. We do however observe the golden rule for all holding tanks. ‘Don’t use it unless you have to’.

There are plenty of articles in the yachting press to show you the pipework options but if you want more details please get in touch.