Nolan Wells' Body Was Found Close To Where He Was Last Seen, Rescuer Reveals

Brian Trascher helped search for Nolan Wells by air before the 18-year-old's body was found along Horn Island's shoreline ... and he believes dangerous water conditions may explain how Nolan ended up surprisingly close to where he was last seen alive.

The United Cajun Navy vice president tells "TMZ In The Know" ... weather conditions forced his team to switch tactics as the search stretched into its second day -- ultimately taking to the sky to cover more ground.

Brian says he and the pilot had been searching for about two hours on July 6 when they noticed several law enforcement boats converging on the northwest tip of Horn Island ... and they swung in close and saw a body floating face down in the water near shore.

From roughly 400 feet in the air, Brian could not see Nolan's face or identify any potential injuries ... but he says the body matched the description and it was awfully close to Nolan's last known location.

Brian also offered his theory about what may have happened -- stressing he’s a search-and-rescue professional, not an investigator.

Based on where Nolan was found, Brian believes a rip current may have initially carried him in one direction ... before a change in the tide brought him back toward the beach.

Brian says what surprised him most was how close Nolan washed up to the last place he was seen alive.

As TMZ previously reported ... Nolan was laid to rest Monday in Ocean Springs, Mississippi, with Rev. Al Sharpton officiating the funeral.

Nolan's family has cast doubt on theories that he drowned ... claiming he was a strong swimmer.

Sharpton offered $50,000 for information leading to an arrest and conviction in Nolan’s death ... and announced Tyler Perry would match it, bringing the potential reward money to $100,000.