As the owner of an underwater diving shop, Pat Beach was expecting a visit by the FBI. He was not disappointed.

FBI Agent Mark Nelson, from the Everett office, stopped by Beach’s Oak Harbor Dive Center late Monday morning. Thanks to wide-spread news coverage of the investigation, Beach knew what was up. And he had no trouble picking out the FBI agent from his regular customers. “He looked like the real deal,” he said.

There was little doubt what the agent wanted. “Everybody knew what they were looking for,” Beach said shortly after Nelson left the shop. “Terrorists learning to dive.”

Beach has owned the shop for about seven years, and that’s the time span the FBI was interested in. The agent simply asked about any suspicious characters and inquired about people who have taken dive classes. He was shown the list, and took down a few names before exiting the store.

The FBI issued a bulletin May 23 stating, “Recent information has determined that various terrorist elements have sought to develop an offensive scuba-diver capability. There is a body of information showing the desire to obtain such capability.”

Following the memo, agents began visiting every dive shop in the country.

The FBI’s Seattle office did not immediately return a phone call Tuesday. But an Associated Press news story quoted spokesman Ray Lauer as saying, “We’re pulling records and interviewing to find out if anything sticks out as being unusual in terms of clients.”

Beach said none of his clients through the years have seemed suspicious. One thing the FBI was looking for, according to the AP story, was the names of students who enrolled in dive courses but did not get certified.