Smit, Thrush, these are grey reef sharks, harmless to humans, in fact pretty scared of us most of the time, you have to find a spot and sit there waiting while they get used to you.

Scuba eqt costs min £500, then the sky's the limit (that's fins, jacket, regulators and gauges). Usually hire the tank and weights since they are too heavy to carry on an airplane. Don't get me started on underwater photography 'cos' that's loads more money to do it properly...

Most rent the equipment to be fair, it costs me around £120 a year to get it serviced which is more than rental for two weeks, but I have the knowledge that I know my gear and it suits me as I chose it.
Training with PADI (don't know about others) is 3-5 days after which you are pretty much free to dive with a partner who is also trained. Not allowed to dive on your own for safety reasons.
Again, once you have started training, the sky's the limit, there is soooo much to learn...