There isn't a water pressure gauge on the dash of Journey On, which also has a 150. There is a pitot tube pick up at the bottom of the lower housing, but I'm not sure where it ends up on the dash, or what it does there. It would only indicate through-the-water speed, though.
There is an coolant overtemp sensor, which sounds an alarm and shuts the engine down, but no gauge there.
There's a fuel pressure gauge on the dash and someday I'd like to find out why it varies while the RPM's are steady.
I think the only water pressure gauge is the pee hole.
If you find out different, my apologies.
Boris