I have long hair and it gets very tangled out snorkeling. I have discovered the 'silk' serums work perfectly for combing out hair after a boat shower.

For long hair, try to encourage them to brush their hair topside as much as possible, otherwise a lot of hair down below that gets stuck to all the bare feet and inevitably ends up in the bunks.

Showers on the stern, or at least washing hair on the stern is required on our boat. Then use the silk serum as the conditioner - it is a 'leave in' type product and then you don't have to use a lot of water to rinse out conditioner. The comb or brush will just glide through the hair, all tangles gone. It is miracle stuff!