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14 March - NOMAD is deployed and tested

Another fine day at sea! And a busy one! We set up to deploy NOMAD first thing in the morning. After running a few tests, we retreived it and got extra practice in launch & recovery while the seas were pretty calm. Tom Bethge worked out a better system of deployment, including a couple of new cleats welded to the deck, and some new hand signals.

The ROV NOMAD being retreived from the water.

It is now 1645, and NOMAD is down with 4,000 feet of cable out. All systems seem to be working, and the deployment was smooth. Although this test will impose a delay in reaching the site, if we run into any problems which require spares we can get back to Honolulu before they arrive, or maybe even divert to Johnston Island for pickup. In the interim, we had fresh mahi-mahi for lunch, and then held another video-taped RENAV session.

The ROV NOMAD being retreived from the water.

SURVEY PROGRESS

In Area A, Southern Portion (including Western Extension), we covered 367 sq-nm (square nautical miles), including 97% of the planned 350 sq-nm area. (This has been updated, because we picked up one missed area from Line 18 when we returned to Area A later) Our overall rate of coverage, including all equipment down time and turns, was just under 1 sq-nm per hour. During the later stages of the search, when NOMAD was continuously deployed, we achieved 1.1 sq-nm per hour.

In the Southern Extension, worth 72 sq-nm, we covered virtually 100% and even some areas outside the boundaries, so our coverage was 93 sq-nm. Coverage rate was 1.0 sq-nm/hr.

We returned to Area A, and search 8 lines in the Central Portion, designated 1N - 8N. This portion was worth 136 sq-nm, and we covered 100% of it. Area coverage was 151 sq-nm, and the total to date is 611 sq-nm. Our rate increased to 1.1 sq-nm/hr. We have met our coverage goal in 26 days of survey, and have 14 days remaining of the planned 40-day search. If we are able to complete the remaining search at the rate we are achieving, we will cover over 900 sq-nm total, a remarkable accomplishment. Of course, we hope to quit early owing to a discovery!

One very encouraging and remarkable fact was the increasing periods of deployment for NOMAD. The first time in the water, it was down for 18 hours. The second time, 43 hours, and the third 65 hours. After a fourth deployment of 71 hours, we had things pretty well fixed up and it stayed down for a record 257 hours, nearly 11 days of continuous operation. And it could have gone longer, as it was retrieved for operational and maintenance reasons, not for repairs. Great job by the ocean engineers! If we can continue that performance, our search efficiency will be at about the theoretical maximum.

Later ...

NOMAD continued to perform at near perfection, although I doubt we will break our record earlier in the mission of 257 hours of continuous operation. During the Central Portion of Area A, NOMAD operated for almost 5 days (111 hours) before needing a comp oil refill, which was accomplished during a turn with a loss of less than 2 hours downtime. So far, we have logged 600 hours of survey, with less than 20 hours (3%) maintenance time. This is superior performance, and you all deserve congratulations for your efforts. 'S FIND IT AND GO HOME!