That is a juvenile scalloped hammerhead. Hard to tell in the photo but looks like a female due to lack of claspers.

There are sharks in the area, not so many in the various local bays as they have been overfished, they now tend to be further offshore.

Not too far north of Tenacatita I have seen large female (3.5m long) scalloped hammerheads and also a decent 3.5m to 4m long bull shark that have been caught not too far offshore. The bull shark was actually caught off the beach in Majahuas just in front of Tomatlan.

Diving not too many years ago near Blue Bay I saw a nurse shark, and diving off Manzanillo on the open ocean side years ago on the Zeta Gas depot i saw what i think was a large hammerhead only about 400m offshore.

The problem apart from local fisherman using the longlines and killing many sharks, is the tuna companies in Manzanillo, they absolutely decimated the local shark populations years ago chasing the tuna schools and bait balls, hence not so many sharks close to the shore nowadays.