sentences:  Before the development of scuba, scientists were making underwater observations of the marine environment using snorkels, freediving, and surface-supplied diving equipment.The earliest recorded scientific dives were done by the French zoologist Henri Milne-Edwards in Sicily circa 1844 in a surface supplied helmet to a depth of 25 ft.The first recorded U.S. scientific diver was Dr. William H. Longley, starting in 1910, and who made the first underwater colour photograph with National Geographic staff photographer Charles Martin in 1926 off the Florida Keys in the Gulf of Mexico.