One of the most exciting dives you can do is a tuna pen dive. This type of dive came as an offshoot from the tuna farming industry. One of the most accessible places to do one of these dives is in Malta, where the tuna farms are close to shore and only about a 15 minute boat ride away. The first thing that happens when the five boat pulls up to the entry point is that a farm hand will feed the tuna before you go down. This causes them to all swim in a clockwise direction, causing a mini whirlpool.
If you deflate your Buoyancy Control Device and let yourself go with the flow, you will find that you will immediately be taken down with the flow that the fish have created by all swimming in the one direction. These fish are seriously huge in size and the largest of them are about as big as a Harley Davidson. One thing to keep in mind is that some of these fish can be quite old and if they are swimming on the far outer reach of the shoal, it probably means that they are a bit blind, this is even more evident when you look at their eyes, which can go cloudy. It is a good idea to give these fish a wide berth because if they hit you, they could do some serious damage to your equipment and even injure you.
If you are brave enough, you can swim against the shoal and the amazing thing that you will find is that the fish will swim directly at you, but will veer off as soon as they get really close to you, sometimes literally with inches to spare. If diving with giants sounds like the thing for you, you really should try it.