I suspicion my problem is the weight of the hatch
covers I keep on them, but to keep them from slamming shut in the middle of the night and scaring us, I cut short pieces of 3/4 PVC pipe and use them as props.
Cut several of different lengths.
In other words near as I can tell there is no friction adjustment.
There are I believe commercially available hatch
hold open struts if PVC is too Ghetto for you.
Sorry too early in the morning, I see you said port lights, I assumed hatches.