prepares to set a world record for the longest salt water dive. a dive instructor for 12 years, alan has the freshwater record staying submerged for five days though he suffered from deprivation. >> the lake is not very clear. it is really isolated the i have visibility, as low as 8 inches. so just like locking yourself in a closet. >> reporter: alan says this dive will be easier because it is on a shallow reef, with good visibility off lauderdale by the sea. >> got to have jimmy buffet when you're under water for a long period of time. >> reporter: he will be listening to music on a special underwater speaker he invented. alan says the big waves really won't bother him. he is going to be about 15 feet below the surface and will have an anchor line he can slip into. his support team though will have a problem with it because they're going to be shuttling tanks out to him on the surface. while submerged for three days. 72 hours. >> 72 hours. >> underwater. >> underwater. >> reporter: he will not eat but he will drink. using a gatorade twist cap