Shore diving basically means diving from the shore rather than from a boat.  Some people consider shore diving to be a lower form of diving, but this is highly unfair. Some fantastic dive sites can be found just off the shores and there really is no need to take a boat if you have some fantastic diving opportunities right on your doorstep. Furthermore, shore diving can sometimes be very strenuous and challenging, so it is not as most people think just something for beginners to the diving world to take part in.