Abstract: A trap suitable for capturing a marine animal in open water without harming the captured animal is disclosed. The trap includes a pen having top and bottom ends. A portion of the bottom of the pen includes a flotation element which is sufficiently buoyant to support a substantial percentage of the pen above the water line. The pen further includes a top rim which has an interior opening large enough to receive the captured animal. The platform is slidably coupled to the pen. The platform serves as a flotation device that is suitably buoyant to support the weight of the animal sought. A trap door within the platform is designed to release when an animal climbs thereon. When the trap door is actuated the pen is released from the platform and rises vertically relative to the platform to capture the animal.