got a light scratch in my white vinyl seat anyway to remove it?

Remove the seat......... Sorry, but vinyl seats aren't like Paint.... You could try some vinyl dye to add color to the scratch, but the scratch will still physically be there.

Got a friend in the car business? They have guys that fix that stuff all the time on their trade-ins. They are mobile repair guys so they'll come to the boat. It will give you a few more years out of it and by then you'll have added more.
Just fixed a tear in mine. Can't tell it was fixed.

some of those mobile interior guys are amazing, good call. You almost have to know someone that knows someone though, its a very transient occupation and most do not list in a phone book or anything.

Contact a high end dealership and ask to get in touch with the guy that does the interior repair.

My guy can fix anything and you would never know.