I've had some wonderful experiences swimming with barracudas.
If you approach them at a 45 degree angle you can get very close before paralleling off to swim beside them. I make and keep eye contact and there is something very spiritual about this connection.
By holding my camera steady, in position, through out I can get some good footage.
The sea creatures are just as alive and interesting as any land critter.
The key is to never have the animal feel trapped. I've had times where a barracuda has followed me throughout the dive.

Harriette
Take only pictures leave only bubbles