840 Down (2004)

From publisher blurb:

Four to six 4th-level agents may play (though the serial’s challenges and XP rewards are tiered so that the serial can be played by up to six agents of levels 9, 14, or 19 as well).

The agents are tasked with retrieving essential planning documents from a crashed 747 belonging to the Franchise shadow cell. The villainous organization uses the converted jumbo jet to discreetly transport VIPs and items between stations and action sites.

The aircraft suffered an as-yet unexplained malfunction, crashing into the Arabian Sea 150 miles from the port of Bombay. The agents’ initial orders are to dive down to the jet, recover its ‘black box’ flight recorder and a briefcase handcuffed to one of the passengers, and trigger the vehicle’s self-destruct mechanism so it doesn’t fall into anyone else’s hands.

Unfortunately, the aircraft is submerged in 1,000 feet of water — far deeper than conventional diving equipment permits. The team is provided with sophisticated experimental gear, however, allowing them to travel to the wreck and return without the usual lengthy stay in a decompression chamber.