Holding Tank; Toilet - Tayana 37 Operation & Maintenance Manual

The hand bilge pump is generally located around the mast step. The hand
bilge pump serves two purposes -- it pumps the bilge and it pumps the
holding tank. By following the intake line from the pump aft, one will
come to a set of two valves. With one valve closed and the other open, you
can see that the pump clears the bilge. By reversing the closure of the
valves the pump clears the holding tank. A little experimenting will show
you the proper valve operation.
There is generally a third bilge pump mounted on the engine. This pump is
always operating when the engine is running. If your engine has such a
pump it is important to remember that the bilge is constantly being cleared
and a leak might not be apparent by simply looking into the bilge to see if
there is water.

3. Holding Tank

Your 37 has a holding tank system which is legal anywhere. The toilet
may be pumped either into the holding tank or overboard directly. If the
holding tank is used, it may be cleared either through an on-deck fitting or
by the use of the bilge pump as described above. The holding tank is
located under the engine. It should be kept clean by pumping clear water
into it periodically. Detergent is useful if the tank has been used. The inlet
to the tank may be reached by lifting the fresh water tank and getting into
the bilge.

4. Toilet

The toilet is one of the standard U.S. makes which uses seawater for
flushing.
The intake and the exhaust are both below the water line. The intake is
well forward of the exhaust opening. Each opening is protected by a thru-
hull fitting. The exhaust line has a loop, and its thru-0hull seacock is kept
open except when the boat is unattended. By opening/closing valves
located on either side of a "TEE" in the exhaust line, discharge can be sent
overboard (normal) or to the holding tank. (NOTE: Before shifting to the
holding tank, close the overboard discharge valve and then open the
holding tank line valve.)
The sequence for operating the toilet is as follows:
1. Pump, slowly, until bowl is nearly exhausted. Normally this
will require three to six pumps.
IV-18