He was moving quick, I only got one nice full body shot. The name ‘porpoise’ is often used to refer to any small dolphin. However, there is a morphological/taxonomic distinction. Porpoises are found within the family Phocoenidae and one of the easiest distinctions are porpoises flat spade like teeth. In contrast dolphins have sharper conical teeth.
The harbor porpoise one of the cutest marine mammals in my opinion. Found only in the northern hemisphere, they are fairly small usually about 100-150 lbs. Sometimes coming very close to people like this one did.
And no, the first picture is not shot through class or underwater. Just in some very clear water, and I was standing nearly right above. He swam right on the edge by some deeper water with the yellow part above is a huge boulder. I turned the contrast up about 10% and the picture turned out great! Enjoy