The U.S. Coast Guard is investigating how a Florida tourism company could leave behind two tourists while they were scuba diving in shark-infested waters.

Paul Kline and Fernando Garcia Puerta were rescued by a private yacht just before sunset after clinging to a fishing buoy for over two hours.

We could see two divers with all their equipment and an inflated red tube, the yacht's captain, Elie Trichet, told the Miami Herald.

The tube is commonly used in diving to signal when one has come out of the water.

You could notice a strong feeling of relief, Trichet added. They'd been clinging to that buoy for two hours hoping somebody would rescue them.

Trichet's 82-foot Sunseeker yacht was headed back to Miami from Key Largo when the crew spotted the stranded divers.

RJ Diving Ventures Inc., a Miami Beach-based boat operator, took a group of 30 people, including Kline and Garcia, diving in open water about three miles off Key Biscayne on Sunday.

However, when Kline and Garcia surfaced, the boat was gone.

We were in shock, Kline, 44, told the Herald. We could have easily died.

Kline, a certified deep-sea diver visiting from Austin, Texas and Puerta, a tourist from Spain, had never met before the trip but came close during their ordeal.

Kline and Puerta say they paid $85 for the four-hour trip, which included two dives at different sites. They were on their second dive when the boat picked up anchor and left without them.

The pair claims to have been underwater for fifty-five minutes.

They told the Herald that they initially thought that the boat had left due to some sort of medical emergency with another diver. However, when it never returned, they realized they'd been forgotten.

Kline, a married father of six, told WSVN-TV that he could only think about getting back to his family while stranded in the water. However, as the ordeal continued, he began thinking about the 2003 movie Open Water and recalled that it doesn't end very well!

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RJ Diving Ventures claims they use a method of accounting for divers that involves checking divers off of a list once they have returned to the back of the boat, according to owner Robert J. Arnove.

I do not know how the two divers got checked off without them being on the boat or who is to blame, he told the Sun Sentinel. We are still trying to figure out while devising a further failsafe system to prevent this from ever happening again.

Captain Mike Reach was also unclear how the incident happened.

Everybody is OK, no one is hurt, everyone is happy. That's all, he told the Miami Herald.

Sasha Boulanger, owner of South Beach Divers, which organized the trip, met with Kline Tuesday to apologize.

However, he said the incident was the fault of RJ Diving Ventures, the boat operators he contracted to take the divers out, and not his own company, which he said has an excellent safety record.

We are the ones who facilitate the trip and connect A with B, Boulanger told the Miami Herald. I must assume a certain degree of responsibility, but unfortunately, this falls on [RJ Diving]. They are in control of the divers and their security.

According to its Web site, RJ Ventures has been in business since 1982.

All calls to RJ Diving Ventures went unanswered on Wednesday and the company's Web site appears to now be down.

According to Coast Guard spokeswoman Sabrina Elgammal, the incident is under investigation.

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