California's giant sea bass and Florida's goliath grouper (formerly referred to as jewfish) are both very large protected species that are incidentally caught by recreational and commercial hook and line anglers. When these fish are brought to the surface, the air in their swim bladders expands greatly, making the fish so buoyant that it cannot swim back to the bottom when released. A release device was designed and manufactured to allow commercial and recreational anglers a means of safely releasing large bottom fish with swim bladders. A prototype was built from which changes were made before a final product was produced. The final product was tested in the field on giant seabass and goliath grouper. Fish captured and released with this device were shown to survive through the use of acoustic tagging and tracking. Twenty-five of these devices were manufactured for the distribution to commercial and party boats that routinely encounter these large protected species.