Saturday, April 13, 2013

Deployment Prep

Before getting started on our survey dives and instrument deployments, we needed to investigate what equipment was available to us, and what additional materials were required. We spent the morning checking out our dive boat and the shore lab - the latter of which is well equipped for our purposes. The vessel appears to be seaworthy; a short exploratory boat ride to check out some of our nearby sites confirmed that, while rather low in the water, we were comfortably on top of most of the swell. 
Inspecting our dive boat (Photo: T.A. Mooney)
Part of the reason why we selected deployment sites on the south side of St John was that typically this area is protected from much of the wind. Not so at present - currently the wind is coming out of the east, which sends some fairly large swell into the bay in which some of our potential deployment sites are located. 

After ensuring that all was in order for a full day of diving tomorrow we set out for Cruz Bay, the main town in St John. In order to ensure that our instruments do not move during the 4-month deployment period we will have to build heavy concrete moorings. So today we purchased ten 80-pound bags of concrete, forty feet of steel bar, and a number of fittings to which the instruments will be attached. A good mooring is critical here - the instruments need to be able to withstand the hurricane season, which starts up in a few months. 

Our first survey dives start tomorrow morning and the concrete will be mixed and poured in the afternoon. The visibility on a quick afternoon snorkel today wasn't great; hopefully it will improve in the coming days. Limited visibility did not, however, prevent us from observing turtles and a medium-sized cownose ray that searched for, and subsequently attacked, a number of benthic mollusks.
Aran navigating the dive boat on our exploratory excursion (Photo: S. Zacarias)

No comments:

Post a Comment