The USS Ohio, a 560-foot former ballistic missile submarine converted to carry SEALs and Tomahawk cruise missiles, was a sight to see when the media was allowed on board last month in Pearl Harbor.

A future visit by the USS Michigan, another of the converted "boomers," should be even more impressive.

The Michigan is expected to test out the Advanced SEAL Delivery System, a mini sub for commandos that rides piggyback on the big host sub.

Trident ballistic missiles were removed from the Ohio, Michigan, Georgia and Florida, and the subs are being retrofitted to carry up to 154 Tomahawks and more than 100 commandos.

The pairing of the Advanced SEAL Delivery System, or ASDS, with the Michigan, expected in 2008, will be a high-tech special ops match-up, but the future of the ASDS remains uncertain.

The ASDS, which arrived at Pearl Harbor in 2000, was heralded as leap-ahead technology that would deliver SEALs dry and rested rather than shivering and cold from the existing SEAL delivery vehicle, a cramped open-water design requiring scuba tanks.

But there remains only one ASDS in the world, and the Northrop Grumman effort has spiraled to more than $885 million, according to a May U.S. Government Accountability Office report. The 65-foot mini sub originally was expected to cost about $80 million.

There have been battery, noise and propulsion problems with the sub, one of U.S. Special Operations Command's biggest investments.

GAO also notes contract oversight issues. A 2005 delivery order contracted for a replacement hydraulic reservoir for $1 million. The contractor said it needed $444,000 extra, the Navy reduced the scope of the work, and reauthorized the job at $937,000, GAO said.

Two days later, the contractor said the cost for the job had almost doubled to more than $1.85 million, according to GAO, and as of December of 2006, a further modification to the order increased the estimate to $2.8 million.

The ASDS program has invested more than $26 million since 2000 to design, develop and integrate a new lithium-ion battery, the federal agency found, and the Navy has invested more than $1.5 million to redesign the first ASDS propeller.

In April of 2006, the Defense Department canceled plans for follow-on ASDS boats and directed the Navy and Special Operations Command to establish an ASDS-1 improvement program.

In February and March, following 15 improvements, nine under-way operations were conducted off O'ahu for a total of 113 operating hours, with no failures. Follow-on operational testing is scheduled for the second half of fiscal 2008.

IN BRIEF

KANE'OHE COPTER GOES BEYOND LIMIT

In 1966, Marine Heavy Helicopter Squadron 463 received the first CH-53A Sea Stallions in the Marine Corps.

The squadron made the first of several Vietnam War deployments that same year, and saw duty in the 1991 Gulf War.

It had been a long time since the more than three dozen CH-53D Sea Stallions at the Marine Corps base at Kane'ohe Bay had been in a combat zone, short of five of the helicopters flying missions in Iraq in late 2004 and early 2005.

But that started to change in 2006. About 175 Marines with HMH-463 deployed to Iraq, and were later replaced by another Kane'ohe Bay squadron, HMH-363, and then HMH-362.

HMH-362, which recently returned to Hawai'i, set some new records. "Aircraft 23" became the first aircraft of its type in the Corps to reach 10,000 flight hours.

A CH-53D has a service life limit of 10,000 hours, and special permission had to be obtained to fly beyond that mark. Back in Hawai'i, engineers will evaluate the aircraft to see how much longer its use can be extended.

ISLE MARINES TRAIN FOR DEPLOYMENT

Approximately 1,000 Hawai'i Marines with the 2nd Battalion, 3rd Marine Regiment recently left for training in southern California in preparation for an upcoming deployment to Iraq.

Battalions from Kane'ohe Bay have been on continuous rotations to Iraq since 2004, when the 1st Battalion, 3rd Marines slugged their way through Fallujah.

The 2/3 Marines who went through exercise Mojave Viper will replace the 3rd Battalion, 3rd Marine Regiment early next year in the Fallujah area.

BONHOMME RICHARD PAYS QUICK VISIT

The USS Bonhomme Richard, an amphibious assault ship, made a one-day stop at Pearl Harbor on the way back to San Diego from the Persian Gulf.

The aircraft carrier-like vessel arrived on Friday, picked up family members for what's known as a "tiger cruise," and left on Saturday for home.

The USS Bonhomme Richard, USS Denver and USS Rushmore participated in counter-terrorism and security efforts in the Gulf region.

PEARL-BASED SHIPS JOIN STRIKE GROUP

The Pearl Harbor-based Port Royal, a cruiser, and Hopper, a destroyer, are scheduled to leave today to join up with the Tarawa Expeditionary Strike Group, which departed Nov. 5 for a six-month deployment to the western Pacific and Persian Gulf.

More than 5,500 Sailors and Marines make up the Tarawa strike group.

Reach William Cole at wcole@honoluluadvertiser.com.