For what it is worth, Dick Tuschick from Rhumbline Yacht Sales issues this advice, which we have used extensively:
Keep the transfer valves open for the forward tank and keep the toggle switch set for transfer aft (this is what you will want to do almost 100% of the time).
Make sure the transfer valves on the aft tank are always closed, except when transferring fuel.
When you wish to transfer fuel aft, remove the wood floor covering for the aft tank.
Open both transfer valves.
Turn on the breaker switch for the transfer pump.
Sit still and watch the fuel gauges until the desired amount of fuel has transferred (do not get involved with something else or you could overfill the aft tank).
Do not bring the forward tank less than about 1/3 full. If you expose the pickup of the transfer, you can get an airlock.
When done, turn off the breaker switch.
Close both transfer valves.
Replace the wood floor cover.
Note, since the forward tank is somewhat higher, if you accidentally leave the transfer valves open, gravity can transfer fuel, which you want to avoid.
This method can be used while underway with no need to leave the cabin as we have done many times.
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade