Drysuit neck gasket - how tight?

I’ve never bothered to trim the neck gasket on my drysuit because I really didn’t notice it once I was on the water. But I recently used a drytop with a wider gasket, and it was noticeably more comfortable. So I am going to trim the drysuit gasket.

My neck is 15 inches at its narrowest (though my shirt size is 16 to be comfortable). How much narrower should I trim the gasket opening to be -maybe 14"? Would that give it enough “hold” that it won’t implode when I’m directly upside down getting ready for a roll? Thanks.

whoa there…
If you never noticed it when it was on, why would you want to go and trim a whole inch?



Just trim one ring off - look on the inside of the gasket. Wear it for awhile and if it doesn’t bother you leave it there.



If you trim to far, you won’t have any contact and will need to replace the gasket.



Suz

not a whole inch
I wasn’t planning on trimming a whole inch. But it is clear that my gasket has been much tighter than necessary, and I am curious if people have found a rule of thumb for how much smaller the circumference of the gasket should be compared to the circumference of the wearer’s neck (in my case 15 inches) to get a secure seal. Also curious whether people have ever had the experience of a seal that is secure when submerged a foot but that gives way when submerged 3 feet.

About the depth thing, maybe it is that
when you are deeper under the surface, the air inside the suit is trying harder to push out through the neck gasket. When some of it blorts out, some water may slip in.

Follow Suz’ suggestion…
…and just trim a little at a time until it’s comfortable. Whatever works at the surface will work at depth, too. The person who showed me how comfortable a neck seal should be was a dry suit diver. He could easily pinch the seal and lift it off his neck, but he said it never leaked at depth.

a ring at a time
until comfortable

before trimming
try putting a large coffee can in the neck for a few days then try it on. It worked for me and it may for you. Trimming is ok but if you read the warranty on most newer suits, trimming will entirely void it.

thanks
good advice - I’ll go a ring at a time (I’ve already stretched for days with my own neck as much as a coffee can will do, so I think I’ve reached the limit there). It’s good to know that what’s good at the surface will be good when upside down. Thanks.