Timeline of the Explorer's Sinking

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Press reports and accounts from credible sources suggest the following timeline:

1. She entered Bransfield Strait on the 11 day of an 19-day late-spring sailing.
2. Seas were relatively calm; winds were benign; but Explorer was traveling through expansive, low-density "band ice" when the breach occurred.
3. The report of a hull breach occurred in pre-dawn visibility (i.e., twilight) at 3:20 GMT. Ship speed at the time was reported as "slow" and within normal operating protocol.
4. She was passing through familiar waters and on a fairly well-beaten path far from shore.
5. Initial reports from G.A.P Adventures suggested a small breach about the size of fist. Two days later it was reported that a hull crack had occurred that spanned at least two compartments.
6. Following protocol, the ship captain immediately signaled an SOS and sailed westward for open waters which he reached within one hour.
7. Early morning photos (after full sunrise) show the vessel floundering in calm ice-free waters and listing 30 degrees to port. Passengers were transferred to life-rafts and zodiacs.
8. Initial media reports indicated that the vessel lost power after which the captain relied on mobile pumps and auxiliary generators to evacuate flooded compartments. These were insufficient to save the ship.
9. The large cruise ship, Nordnorge, arrived 4 1/2 hours after the distress call and began taking on survivors. Also on scene was Endeavor, another small vessel operated by Lindblad Travel.
10. While Explorer fought for her life, she began drifting eastward back into the band ice. Sea conditions also began to deteriorate slightly. Finally, 15 hours after the hull breach, the vessel went down in deep water with 50,000 gallons of light diesel fuel oil, 24,000 litres of lubricant and 260 gallons of gasoline. A 1.5 km slick lengthened to over 1 mile before the area was covered with ice.

Captain Says Extensive Flooding Sealed Her Fate

In an interview with Sydney's Thumb, Leif Skog, a previous captain of Explorer, stated that if the hull damage had been limited to one compartment, the ship would have survived its wound. Unfortunately, the flooding of two compartments, including the engine compartment, reduced pumping capacity. This probably sealed Explorer's fate.

An unexplained oddity in the sinking of Explorer is that her breach seems to have occurred "amidships" rather than in a forward compartment where ice collisions are more common. This has fueled some expert speculation that ice may not have been the cause of the breach.

A report on the sinking is expected in December and will be issued by Liberia, the licensing flag-state. No other jurisdictional review or investigation is mandated because the vessel sank in disputed territorial water. The highly respected British Maritime Accident Investigators International Forum, MAIIF, has agreed to participate in the inquiry, but has stated that it is not conducting an investigation of its own.

PAH Impacts Cause for Concern

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A comprehensive review of diesel oil impacts by the United Nations Environmental Program (UNEP 1997) supports their concerns about PAH's. It identifies past diesel spills in polar waters that caused at least short-term impacts. One at Arthur Harbor in 1989 resulted in a "high mortality" among limpets and a "small effect" on macroalgae. Partial recovery was observed one year after the spill.

In 1989, Bahia Pariso ran aground near Palmer Station on the Antarctic Peninsula and leaked 52 tons of heavy fuel oil. This spill killed as much as 50%of the mollusks and marine algae in the intertidal community but had "little effect" on the sub-tidal community. According to Ducklow, Co-director of the Long Term Ecological Research Station at Palmer, the Pariso continued to leak 15 years after the accident.

PAH's Can Toxify Sea Ice for Algae

Paradoxically, the UNEP review also suggests that diesel oil is generally more toxic than crude oil. This is because greater percentages of PAH's are present in lighter fuels. Another issue described in the review and potentially relevant to the Explorer accident is die-off and toxification of algae that grow on the undersides of ice. As noted above, the water in which Explorer went down was soon sealed by sea ice which will certainly be exposed to rising PAH's. If this ice provides habitat for algae, feeders such as krill would likely be affected. As indicated by Ducklow, this kind of algae is a critical source of food for krill.

As of early December it appears that The Antarctic Treaty Organization seemed intent on monitoring a variety of impacts. No details have yet been released on what the environmental teams will be monitoring.