Members of the Clay County Sheriff's Office received some specialized help with a year-old rural residential burglary investigation.

The Arnolds Park/Okoboji Fire Department Dive Team was called at about 8:45 a.m. Sunday to Stolley's Gravel Pit in west Spencer. Lt. Jason Kirschbaum of the dive team said the exercise doubled as a training opportunity for the volunteers who form the unit.

Deputies with the Clay County Sheriff's Office called the dive team after receiving a tip from an informant about the approximate location of three weapons, which were thrown into the water-filled pit near Spencer's industrial park.

Kirschbaum said two pairs of divers went into the 45-degree water. The weapons were tossed into a 15-foot-deep part of the pit. There is zero visibility at that depth, so divers had to search the bottom of the pit with their hands. The first team went into the water at about 9:15 a.m. They found a shotgun seven minutes into their dive and a box of ammunition a minute later.

"Two more divers were deployed to relieve the first two divers," a joint statement from the Clay County Sheriff's Office and Arnolds Park/Okoboji Dive Team said. "Approximately 10 minute into the search the third and final shotgun was located."

Kirschbaum said requested searches for property are not unusual for the dive team, which dates back to the 1970s. Over the department's history, it has also helped Fort Dodge authorities search for a murder weapon, which was thrown into water.

Nine divers were on hand for the Stolley's Pit search. They were on the scene for about an hour.

Deputies have made one arrest in the investigation, with more on the way. First Deputy Duane Bates of the Clay County Sheriff's Office said federal firearms charges will be added once the final arrests are made.