Saturday, August 22, 2009


Today was a repeat of yesterday -- if anything a little worse. We had steady 15 knot winds for most of the day picking up to near 20 later on. We surveyed for pilot whales until afternoon when it became too strong to search for anything visually. As yesterday, we continue to search acoustically and some beaked whale clicks were detected during the day in areas where we had sighted them before. So they are still where we expect them to be and we can detect them using our acoustic assets, but even being right on top of them it is impossible to spot them visually in the Beaufort 5 wind conditions.

The Beaufort scale is an empirical measurement of wind speed that is related to sea conditions. To give you a sense of how remarkably calm we need the conditions to be, consider that the scale goes from 0-12 and 5 (our wind for much of today) is categorized as a "fresh breeze" of 15-20 knots (29-38 km/hr or 16-24 mph) and the resulting seas have moderate waves of some length, many white caps, and small amounts of spray. For sighting and tagging beaked whales, we need Beaufort 0 ("clam" with winds <1 knots), Beaufort 1 ("light air" with winds 1-2 knots), or Beaufort 2 ("light breeze" of 3-6 knots) conditions. Anything Beaufort 3, a "gentle breeze" of 7-10 knots (12-19 km/hr, 8-12 mph), or above makes it difficult or impossible to visually detect and tag beaked whales. Beaufort 3 and 4 ("moderate breeze" of 11-15 knots) can be workable with pilot whales and other cetaceans, but at Beaufort 5 we tend to put the covers on the big-eye binoculars, not because we can't take it but because it isn't worth looking.

We continue to refine and cross-calibrate all our detection systems and await the opportunity. Tomorrow looks as bad in terms of wind and the seas may be building with the steady wind from the east, though we have learned not to put too much faith in weather forecasts. We are moving to what we hope may be a better area in terms of weather where beaked whales have been spotted previously.