SEA Currents: Corwith Cramer
October 23, 2015
Thoughts from the Aft Cabin
75 miles SW of Gibraltar
The Automatic Identification System (AIS) transmits navigational data between ships, allowing them to see one another as little boat-shaped icons on a screen, sometimes as much as a hundred miles away. Ship names in prosaic boldface text occupy the space next to each vessel on the plot. The cruise ship "MSC Splendida", bound for Malaga. The merchant vessel "Eide Wrestler", for Algeciras. The "Interlink Levity", for who knows where.
A click of the mouse provides the data needed to keep ships a safe distance apart: Course, speed, and, most importantly, the closest point of approach, or CPA. This is the minimum distance that the ship in question will pass to yours-- a direct index of just how concerned one need be as the merchant vessel "Bulk Supreme", (60,000 deadweight tons), trundles by with the kinetic energy of five thousand speeding UPS trucks. Ships at sea, with their giant turning radii and vast inertia, become interested in one another when CPA's drop below 3 miles. CPA's below one mile are usually cause for evasive action, a slow dance of maneuvers taken in accord with a carefully drawn set of international rules.
West of Gibraltar, traffic is dense, and the AIS screen resembles a swarm of ants on a driveway. Ships come and go from the Mediterranean by the thousand each day, and outside the streams diverge like tributaries, rivers of
shipping flowing up towards Northern Europe, south towards Africa, and west towards the Americas. Getting anywhere through this crowd of vessels seems, at a glance, impossible.
In truth, the ocean is a big place, and on most days remains oddly spacious even as the screen fills with information. It is gray and nearly calm this afternoon, with just enough wind to steer by. There is a school of tuna shadowing us, visible through the blue glazing of sea surface, discouragingly uninterested in our fishing line. There is the Merchant Vessel Epic Barbados, northbound to the east of us, and just a silhouette on the horizon. The aforementioned MSC Splendida cheerfully answers our radio call, and agrees to pass at least a mile down our port side
The students are forward, doing drills with the course and top'sl, sails that saw little service in the Mediterranean but will hopefully be more useful to in our run to Madeira and Grand Canary. The tenacious low-pressure system that brought so much chilly rain to the Gulf of Cadiz is slowly dissolving to the southwest, and if the Azores high can re-establish itself, it would mean fair winds for the passage. It's important to always employ
conditional tenses when talking about the weather.
We're only a day back at sea, but routines have easily reestablished themselves, the pace of life on the ship more naturally continuous than that ashore. Hours, meals, watch changes, days and nights more or less equal in
the tasks that need accomplishing. Trainees get science gear ready, bake lasagna, look into the radars, organize teams to handle sail, and count plankton under microscopes, at hours when most people (even college students), are fast asleep. Coming up are project presentations, new destinations, final papers, and the steady satisfaction of knowing a complex world that was utterly foreign to them, just a few short weeks ago.