OPC was once used as a tournament chip aboard all Carnival owned ships -- Princess, Costa, Carninval, etc.
but were discontinued when each cruise line adopted their own NCV chip with their ship's logo on them. Some are still found on the older ships, but have been replaced with a printed match play coupon. And, some casinos still used them at the beginning of each cruise when the casino staff has instructional craps and blackjack demonstrations. Some ships use the OCP higher value chips ($100 to $1,000) for blackjack tournaments only.
Value for a chip that is not smeared or with a worn image is about $8 tops. There are two versions of that chips -- the NCV and "Free Play." The FP is used as a match bet on even money games. Hope this helps.