Allports Island is a boat-access wall and training site in Queen Charlotte Sound opposite Waikawa Bay, where deep water wraps close to the shoreline and lets divers move quickly from a shallow rocky margin into steeper terrain. It is commonly treated as a practical Marlborough Sounds dive for skill work, depth progression, and relaxed exploration rather than for one headline feature. Shallower sections hold anemones and fish around the rock, while deeper water is known for dense tubeworm growth that gives the wall extra texture. The site suits divers who are comfortable with colder New Zealand conditions and want a straightforward Sounds dive with real depth nearby, but without the bigger logistics of outer-coast or major wreck trips.