Powerhouse Cove at Star Island is a wonderful dive. It's a great location to bring advanced classes for a initial boat dive. It's very protected and generally calm. The bottom is a combination of rocky, ... Powerhouse Cove at Star Island is a wonderful dive. It's a great location to bring advanced classes for a initial boat dive. It's very protected and generally calm. The bottom is a combination of rocky, reefs with course sand mixed in between. Lots of sea life and kelp. You can drop into 10 to 15 feet, depending on where you anchor. You can swim to the sandy shore areas on the island where you can stand, collect yourself, from there you can head southwest towards White Island or west towards Lunging Island. You can finds depths of 60+ feet to qualify for an advanced certification.