I have heard of that referred tp as a 'shaft log'
below the stuffing box to the hull cutlass bearing. It is a tube. I have not checked up on my own shaft log in a while and may have to replace it while re-doing the cutlass bearing. On the other hand, mine is a 1967 boat and while I hope the shaft log was replaced at some point it may have been built with a very durable material back then. I need to check this out on my boat more thoroughly so thanks for bringing it up.
below the stuffing box to the hull cutlass bearing. It is a tube. I have not checked up on my own shaft log in a while and may have to replace it while re-doing the cutlass bearing. On the other hand, mine is a 1967 boat and while I hope the shaft log was replaced at some point it may have been built with a very durable material back then. I need to check this out on my boat more thoroughly so thanks for bringing it up.