Local Boat Aids Navy Search for Plane
Congressional Hearing Provides Glimpse of SWATH's Effectiveness
BY BRAD GRAVES
The 40-foot-long craft left North Island Naval Air Station aboard a C-5 cargo plane Jan. 11, after Navy crews had used it in an anti-terror survey of San Diego Bay.
Navy crews had been cataloging objects on the harbor floor to foil future attempts to mine the bay, said Greg Smith.
Smith, general manager of boat builder Swath Ocean Systems, LLC of Chula Vista, made his remarks Feb. 20 before a congressional subcommittee meeting in El Cajon.
The Navy's Explosive Ordnance Disposal Mobile Unit 7, headquartered at Naval Station San Diego at 32nd Street, operates the craft. An officer representing the unit declined to comment for this story.
Smith told the committee Feb. 20 that Navy crews had surveyed a 3-by-3 & #733;-mile section of Indian Ocean floor in rough seas, and finding nothing, were ready to go on to a wider area. He said he was relaying a conversation he had that morning with a Navy officer.
SWATH stands for Small Waterplane Area Twin Hull. Various builders have turned out SWATH boats for the Navy, according to Navy public information offices. The Navy has just one of the locally made boats, called the MHS-1.
The SWATH's unconventional hull design stabilizes the boat in rough seas.
As they go down to the waterline, each of the boat's hulls narrows to a long strut, which ends with a bulbous lower hull.
"The struts enable the lower hull to ride like a submarine below the surface in calm water, rather than contacting abrupt, choppy seas on the surface," Smith told the Military Research and Development Subcommittee of the House Armed Services Committee, chaired by Rep. Duncan Hunter, R-El Cajon.
Smith said the submarine-like lower hulls have canards and stabilizers that move to counter to the ocean's pitch, roll and heave.
The boat's 4 & #733;-foot draft allows it to operate in near-coastal waters.
According to published reports, the B-1B bomber went down Dec. 12 just after it left Diego Garcia for Afghanistan. Diego Garcia is near the Equator. The four-member crew was rescued.
Smith said his SWATH boat had been working well in 12-foot seas in winds of 40 to 60 knots. He said ocean depth in the spot is about 700 feet.
The boat is small enough to ride in a military cargo plane, on the bed of an 18-wheel truck, or on the deck of a ship, Smith said, adding it can ride without a cradle.
Smith also said his company's boat was used in a recent Navy survey of San Diego Bay, mapping objects on the harbor floor.
Data from future surveys could be compared to the baseline survey to determine if any new objects are on the floor.
"Only six months ago the thought of someone mining an American port was unimaginable," Smith told the panel. "However, it is now fair to say we live under considerably different circumstances."
Two Caterpillar diesel engines power the Swath Ocean Systems boat.
Swath Ocean Systems traces its history to 1979. The Chula Vista company also advertises ferry, yacht and other double-hull models.