A bump in the seafloor

Well, I thought yesterday was going to be the start of “boring is good” operations, but we hit a snag just as we started flying SUESI over the trench axis, where the bathymetry steepens considerably. The altimeter stopped functioning, which effectively means we were flying blind, and the last thing any of us wants to happen is to run SUESI into the seafloor.

After discussing our options with the Captain, we decided the best course of action was to haul SUESI back on deck to swap out the altimeter for a spare unit and use the repair time to turn the ship around to get full data coverage across the trench.

Once SUESI was secured on deck, we swapped out the altimeter, and used the remaining time during the transit to make some adjustments to the Barracudas, which are part of our inverted long-baseline navigation system (more on these in a future post). When we were in position to deploy SUESI again, we did a deck check, only to find that she was no longer willing to output any current. This is the first time in nearly ten years of operations that SUESI has experienced this malfunction.

After stressing about what the cause could be, we swapped to the backup SUESI and did another deck check. Everything was working fine, and we went ahead with redeployment. By just before midnight last night, we were deep-towing ~100 m above the seafloor once again, having only lost about 5 km of coverage near the toe of the trench axis.

It’s been an eventful voyage thus far, to say the least. Knocking on all the wood on board for smooth operations for the remainder of the survey.