Help with a seat post???

[fish4lunch]

Why did the post raise up and how do I fix it? It just went up last time out. It will go down when you sit on it, but then back up (like it's under pressure) when you get up. New to boating and this boat.

 

[dubs283]

Based on photos the control for height is either the lever in pic #1 or the pinch bolt/nut in pic #2

Guessing I'd say the level is for swivel and pinch bolt/nut for height

 

[IlliniDoc]

Have to agree with dubs283 once the desired height is established tighten the pinch bolt on the stem, and the lever would be for the swivel function.