Yes, you do have to chain breed.
First get a Male Blastoise/Wartortle/Squirtle and make sure it know Rapid Spin. Breed it with a Female Kabuto/Kabutops and the egg will be a Kabuto with Rapid Spin, make sure the newly hatched Kabuto is a MALE. Then breed the Male Kabuto that knows Rapid Spin to a Female Tentacool/Tentacruel. The result will be a Tentacool with Rapid Spin.
For more info on Tentacool