I'm not a fan of BLO becaus it doesn't ever really dry or takes forever to do so. Pro Custom is pretty thin and woks deeply into the wood. I think I've read where the tung oil is more water resilient, thus the use in the marine environment. The urethane provides that extra level of longevity and protection plus is a drying agent. When you use wet/dry paper to sand it in, it really creates a great finish. It doesn't Impact color that much either.