If you're looking for a unique experience, don't forget wharves and other man-made structures. These are magnets for exciting life such as marine mammals, fishes, and invertebrates.

Not all wharves are suitable for diving. Heavy surf, low visibility, rusted debris, or unstable pilings can make diving unsafe. Another common hazard is fishing line, which can be difficult to see underwater and even more difficult to untangle.

Before diving a wharf or any other man-made structure, you should check local regulations. Diving is prohibited at some locations, and others require that you inform the wharf staff prior to entering. If these regulations exist, it's usually because hazards exist, and local officials are looking out for your safety.