Fred Bavendam / West Indian Manatee (Trichechus manatus) named Sadie has propeller cuts on the tail, but her calf remains intact, every year boats kill dozens of manatees, Kings Bay, Crystal River, Florida

Sergio Hanquet / Green turtle (Chelonia mydas) swimming in proximity to boat propeller; propellers are a danger to sea turtles. Tenerife, Canary Islands.

Shane Gross / Boat propeller scar runs through a Seagrass (Thalassia testudinum) meadow in The Bahamas. The prop scar is caused by a boat's propeller digging up the root structure of the underwater plant.

David Fleetham / Diver swimming behind the propeller of the wreck of the Hilma Hooker, a 236 foot long cargo vessel that sunk in 1984 off the island of Bonaire in the Caribbean.

David Fleetham / Diver swimming behind coral growing on the prop of the wrecked "Hilma Hooker," a 236 foot long cargo vessel that sunk in 1984 off Bonaire, Caribbean. June 2008. Model released

David Fleetham / Divers ascend past the prop on the wreck of the "Hilma Hooker", a 236ft long cargo vessel that sunk in 1984 off Bonaire in the Caribbean. June 2008.

Cyril Ruoso / Long-tailed Macaque (Macaca fascicularis) mother and young jumping off boat propeller, Khao Sam Roi Yot National Park, Thailand

Cyril Ruoso / Long-tailed Macaque (Macaca fascicularis) climbing up boat propeller, Khao Sam Roi Yot National Park, Thailand

Tony Wu / Southern right whale (Eubalaena australis) fluke marked by injuries that appear to be the result of a propellor strike from a boat traveling at high speed, photographed with the permission of the Depa...

Tony Wu / Sperm whale (Physeter macrocephalus) skeleton of female dubbed Jubilee, on display at the Lee Kong Chian Natural History Museum in Singapore. This 10.6m adult whale was found off Jurong Island in July...

Tony Wu / Humpback whale (Megaptera novangliaea) engaged in bubble net feeding, note the injury to dorsal fin possibly from boat propeller, Chatham Strait, Alaska, USA July, .

Pascal Kobeh / A diver on the wreck of the Bristol Blenheim bomber shot and which crashed in December 1941, Malta, Mediterranean