I've got that same pump as Chris. Yesterday I spent a bit of time checking out how the pressure reads on the gauge. The outcome being that connecting the pipe to the valve opens it but the gauge has a one way Valve at the pump end. This means you can check the pressure even without the pump connected.
So with a note accurate pressure set in the keel we were 5 up on a rolling choppy sea and she preformed excellently. Even when running back in with he swell the boat was more sure footed.
Cheers all, another issues' off the list