My first time fully geared up for scuba diving was at the aquarium in Singapore. For ~$50, they let you in the aquarium to feed, pet and dive for about 45 minutes. There were all type of fishes you can find in there, from sharks to sting rays to turtles. And yet after the dive they also give out a t-shirt. If you ever wanted to try out scuba diving, that would be a place.