How to take a dump on Charlotte in Canada:
(1) Open the small gray plastic input ball valve (align it with the hose). Starboard side, just aft of the aft head bulkhead. Yes it's hard to see. (Check the tank level while your at it -- if the tank is full it will pressurize until it spurts out the hose fittings.)
(2) Twist the gray Y output valve to connect output to the large brass valve.
(3) Open the large brass valve (align it with the hose). only in Canada
(4) Set the little metal switch next to the pump to pump in saltwater.
(5) Pump in a little saltwater to wet the bowl and verify everything is working.
(6) Use the head. (Note: for solids it can help to place toilet paper in the bowl first to minimize contact)
(7) Flip the little metal switch to dry.
(8) Pump the head dry.
(9) Flip the switch to sea water.
(10) Pump the head full of water. Now you are trying to flush the pipes. Strategic use of TP to clean the bowl can be helpful at this point. Figure on about 15 pumps.
(11) Flip the switch to dry.
(12) Pump the bowl dry.
(13) Close the gray plastic input ball valve (handle 90 degrees from pipe).
(14) Close the large brass output valve (handle 90 degrees from the pipe).
If you forget steps 13 and 14, on certain tacks fresh clean sea water
will enter the hull via the bowl, fill the bilge and slosh around. In
extreme cases the boat could sink. Do not neglect steps 13 and 14!
To operate the head in the US, you wouldn't need to dork with the
output (large, brass) valve, but it would be a good idea to verify that
the valve is closed anyway. Turn the Y valve to connect head output
with the holding tank. And after using the head, if you forget to
close the input valve, water will slip past the head pump and enter
the boat.
As for pumping out, open the waste deck fitting, ensure the pumpout
hose has a good seal around the deck and a good seal around the
pumpout machine (amazing how often this breaks!), and use the pump
(follow instructions, ask the harbor master, etc). After a pump, it's
a good idea to fill the tank full of water (either via working the
head or via a water hose down the waste valve) and pump it clean
again. After pumping it clean for the last time add some holding tank deoderizer
.