F250 Oil Pressure

After running my boat about 20 minutes at cruise I backed down to idle and noticed the oil pressure gauge drop all the way down to one bar on the gauge. The engine has about 65 hours on it and it has never done this before. The warning buzzer didn't sound, but I'm still concerned.

Is this normal? Thanks.

[boats.net]

The gauge will show a lower reading at times, If the oil pressure falls below 44 psi the low oil pressure warning will activate and sound buzzer. Your dealer can test the warning system to make sure it's working properly.

I'll take it up to the dealer just to be safe. Thanks for the advice.