Was told that a High Five would be good for watersking off my 21' Imtimadator. I have a 250XS on the boat and that a 815762A46 23" would work well. I looked on E Bay and gound similar numbers, some had A40, A38, only saw one A40, not sure what the A's stand for and also there were sometimed two munbers in the front, in front of the 815. I am just looking for hole shot for skiing.
Oh, do they need to be vented?

