When we see Sperm whales (Physeter macrocephalus) we often encounter groups of females with their calves.
Sometimes a calf can be seen repeatedly diving and surfacing alongside the tail stock of an adult female.
This behaviour is called 'peduncle diving' and is thought to indicate when the calf is receiving milk from its mother (or, in the case of Sperm whales, a surrogate) – see pic. 

(Sperm whale calf peduncle diving)

Cetacean calves do not suckle but receive their milk squirted directly into their mouths.
When seen, the rapid frequency that the Sperm whale calves repeatedly surface, blow and then dive is, for me at least, puzzling.  I would expect the calf to remain submerged for longer and therefore receive more milk.
At least, for Sperm whale calves this does not seem possible, and it seems most calves prefer to take a breath after swallowing each mouthful of milk.

(Sperm whale calf takes a breath before peduncle diving)