Dolphins

Dolphin encounters are typically fast paced with lots of swimming. Individuals in a pod will pass very close to you, but at high speeds so you don't have time to experiment much with light and settings.

Where

Any ocean, most famously the Bahamas and the Red Sea.

DSLR + Mirrorless

ISO: 400
Mode: Tv Shutter Priority
Aperture: (set by camera)
Shutter Speed: 1/500 to 1/1000
Technique: Shoot while following the movement of the animal with your frame to reduce motion blur. 

Point + Shoot

ISO: 400
Mode: Tv Shutter Priority
Aperture: (set by camera)
Shutter Speed: 1/500 to 1/1000

Technique: Shoot while following the movement of the animal with your frame to reduce motion blur. 

Strobes

Typically you will be snorkeling or at the end of your dive near the surface, so you won't need the extra light that strobes provide... Strobes will only slow you down!