On our 10:00 am trip we have the pleasure of watching Parachute be VERY active. This does not happen on every trip. Humpbacks do breach a lot but the odds that it happens during every departure is very rare.
Here you can clearly see Parachutes ventral pleats. The grooves allow expansion so when "he" feeds this area can expand and he can take a huge gulp of water in and filter that water, getting more food with just one mouthful. This makes them more efficient feeders.
On our evening trip Hobo continued our amazing lucky streak. He breached and lob tailed for about 10 minutes, so amazing to see.