After a 15-day expedition, the Endurance Array Team returned to port aboard the R/V Sikuliaq on 7 April having successfully completed the 14th turn of the Endurance Array. The team recovered and deployed seven surface moorings and completed sampling at all recovery/deployment sites. They also deployed and recovered gliders and surface profilers.

Because of the size and weight of the moorings and other equipment, the trip was conducted in two legs. The first leg was primarily off Washington and the second off Oregon. Between legs, the R/V Sikuliaq returned to Newport, Oregon to offload recovered equipment from the Washington Line and load new equipment for the Oregon Line.

The weather was rough when the R/V Sikuliaq first set off from Newport on 24 March. On the first night out, they saw 19-foot waves and 35-knot winds.  The team worked around the weather on the first leg to deploy three moorings and recover four. They also recovered and deployed gliders.

The second leg of the journey brought with it much better weather, which eased the recoveries, deployments, sampling, and other activities.  During this leg, the team worked mostly off Oregon. The team deployed four moorings and three profilers and recovered three moorings, three gliders, and a profiler.

Each OOI deployment brings some technical improvement.  On this deployment, the Endurance moorings are outfitted with redesigned solar panels on the buoy decks. These panels will deliver more power and be more resilient to wear and tear caused by sea lions who often find the buoys an inviting place to lounge.  The redesign was implemented by OOI’s Coastal and Global Scale Nodes team at Woods Hole Oceanographic Institution.

This trip also marked the Endurance Array’s team first use of a OOI’s ROV (remotely operated vehicle). The ROV was used at the Oregon shelf site to recover a coastal surface piercing profiler and its anchor. Throughout the process, the R/V Sikuliaq maneuvered skillfully to place the ship over the target. Mooring lead Alex Wick piloted the ROV through strong currents and limited visibility. It took four dives, but the profiler and its anchor were recovered.  On the third dive, the ROV was used to cut the winch line so the team could recover the profiler, and the anchor was recovered on the fourth and final dive.

The Endurance team also collected CTD samples and biofouling samples to share with researchers at the Smithsonian Institute and Oklahoma State University.  The R/V Sikuliaq returned to Newport on 7 April  with the recovered equipment, which will undergo refurbishment for the next turn of the Endurance Array in September.

“Since 2017, we’ve sailed on the R/V Sikuliaq for six out of nine cruises,” said Ed Dever, the Chief Scientist of Endurance 14. “It’s a match that works well.  From ship handling and on-deck assistance to mobilization of underway science sensors, lifting gear, engineering, accommodations, and food, we are deeply appreciative of the Sikuliaq’s captain, crew, and the ship herself.”