They also sometimes make bubbles under the boats or blow the water at us. Very amusing. You will be able to see and experience many of the whales activities like rolling, blowing and spy hopping.
Rolling and showing the tail and the fin. Some of them are showoffs. Maybe it is the whale's version of synchronized swimming.
Grey whales have barnacles attached to their body. We let the whales choose to approach the boats, so it is not guaranteed to have a personal encounter, ie. touching.