Help with going in forward and reverse

[Termi1]

So I am having an odd problem. I have a 2004 LSV with the 383 hamerhead and a fresh air exhaust. The boat cranks fine and I can get it off the trailer and do some running around no problem.  Once I cut the boat off and float for a while, when I go to crank it up it cranks but I can't get the boat to move in forward or reverse.  Then the engine will rev up a little and everything is good till the next time I cut things off.  Yesterday I had this happen but then the boat would crank and cut off, crank and cut off.  finally everything worked and I was good.  Does anyone have an idea.  I have checked the transmission fluid and it is fine. I did add a half of a quart to be sure.  Also I notice that when underway my oil pressure is running up around 75 when it used to be at 60.

[JasonK]

When you say "crank" do you mean the engine is running? Or crank as in "turning over trying to start"? When you say "cut off" you mean "quit running" right?

To recap: It runs fine and drives fine, you turn it off, then it starts up fine but when you put it "in gear" it won't engage forward or reverse. Then what? While it's in forward gear it revs up and all of a sudden engages forward gear? and then shifts and runs fine all day?

[Michigan boarder]

On 7/31/2016 at 11:33 AM, Termi1 said:

 I have checked the transmission fluid and it is fine. I did add a half of a quart to be sure. 

It is not a good idea to overfill the transmission.  If you lost a half quart, that is another issue.  Does there seem to be any fluid in the bilge?