Edge of the Arctic Shelf

View from the Waterline
This will surely be remembered as the longest day of the cruise for the mooring crew and the ship's Marine Science Technicians and Boatswain's Mates, who operate the Healy's deck equipment and small boats, respectively. The day started just after breakfast with a small boat briefing on the bridge. The Healy has two RHIBs (Rigid Hull Inflatable Boats) to support science or rescue operations. As you might recall from an earlier dispatch, one of them recently received a complete engine replacement. Today was the day to test out that new engine, while the other boat was supporting the mooring crew. I jumped at the chance to ride in the boat that was getting a test run.

My first task was to get into a "dry" survival suit. That's a bit harder than you might think. The suit is essentially a neoprene-lined ziplock bag... which is a great thing to have if you fall into this freezing cold seawater, since it is designed to keep you completely dry and warm. After a bit of wriggling, I finally got the suit on and made my way to the ladder. The boat was already bobbing on the waves below, about 20 feet down the side of the ship. Once settled in, Boatswain's Mate Tom Hines fired up the engine and we were zipping across the midnight blue water of the Beaufort Sea. Unfortunately, the ride was a short one--the new engine started sputtering and knocking, so Petty Offier Hines decided to shut down the engine. That left us bobbing on the waves while the other RHIB helped with the first mooring recovery of the day. After that, they came to our rescue and towed us back to the Healy. I was impressed by the way the boat crews made the best of the unfortunate situation by turning it into a rescue training exercise.

When we got back to the Healy, I switched boats. I wanted to see the mooring operation from the boat crew's perspective. The first thing I noticed is how different the Healy looks from the water. Onboard, the ship feels extremely tall and narrow. From the water, you see just how wide the ship is... No wonder it's so stable! The boat crew plays an important role in safely recovering the moorings. Once John Kemp has sent the release command and the mooring is floating on the surface, the boat crew picks up a hook from the stern end of the Healy and attaches it to the top float. Then, using a giant winch, the mooring is reeled onboard. Without the boat crew's help, hooking that top mooring would be a much more difficult operation.

During one of the mooring recoveries today, the lookouts on the bridge noticed that we had a rather unusual visitor...

Ryan Frazier recounts: "This morning I made my quickest exit from bed yet, when the loudspeaker came through with "Polar bear 600 yards off the port bow." I think about everyone, awake or asleep, jumped at the announcement. Once we were on deck it was a little bit difficult to see, as 600 yards is a long way, and only its head was above water. All we saw was a little white dot, though I could get a somewhat better view through the little binoculars I have. While we watched it kept swimming along, heading off to who knows where. It is amazing to even see it out here, as we are 35 miles from Point Barrow, and even further from any ice. Hopefully we will manage a better view of a polar bear before we finish, though it is still spectacular to see one in the wild at any distance."

As I type this dispatch, the final Beaufort Slope mooring is being secured on the fantail. Unfortunately, one of the three Acoustic Recording Packages did not return to the surface. After waiting for two hours for it to appear, it was surmised that the release had failed. The other casualty was the Arctic winch, which was developed as a means to measure the water column from the top float to the underice surface. Judging from the evidence that was left on the top float, it appeared that the small Arctic winch float had gotten caught in an ice floe and ripped off the mooring. That still makes seven recoveries in one day, an incredible feat. John Kemp & company will be sleeping well tonight. Overnight, Dan Torres and Sarah Zimmermann will be calibrating the mooring instruments so that we can see how accurate their measurements were.

Dan Torres explains: "It is very gratifying to setup and deploy an oceanographic instrument in the harshest of environments, come back a year later, recover that instrument, and find it full of data. After we have the data back, some of it has to be calibrated. This is mundane non-glamorous work but it has to be done. We are mounting the CTDs that come off the moorings onto the SBE911 CTD package. Then we do a series of casts to calibrate the moored CTDs with the rosette CTD (which has very accurate sensors)."

Tomorrow we will be moving farther west, to Barrow Canyon, a steep submarine valley located just off the nortwestern tip of Alaska.