Once we truly get under way tomorrow, we’ll start taking shifts on the Big Eyes. Remember I showed a photo of the binoculars in the March 10 entry? Most handheld binoculars are between 6 and 12x magnification. These Big Eyes binoculars are 25x power, and they’re so big that you’d never be able to hold them steady, even if you could pick them up. So the Big Eyes are mounted on a pedestal that swivels up and down and from side to side. We were trained today on how to use them by Allan Ligon, a research assistant at the Maui office of the Hawaiian Islands Humpback Whale National Marine Sanctuary. He and others have used the Big Eyes to spot marine mammals, but we think this may be the first time this technology has been used to spot marine debris.
We’ll work in two teams of four observers, so each team will be on for a two-hour shift, then off for two hours. We’ll be observing from sunrise to sunset, pretty much 6:30am to 6:30pm. Within a two-hour shift, we’ll swap off every 30 to 40 minutes between manning the binoculars and recording data on the computer or paper, because it can be tiring to look through the binoculars. The binocular stations require that you look through the binoculars and scan the water from ship’s edge to the horizon, and from dead ahead to 90 degrees away from center (straight off your side of the ship). One set of binoculars covers the port side (left as you’re facing the front, or bow, of the ship), and one set covers the starboard, or right, side. As the people looking through the binoculars spot marine debris or marine mammals, they shout (or just say) what they’ve spotted, what direction the binoculars were pointed when they saw it, and how far away the item was. The distance is measured with a set of marks, called a reticle, in the binocular eyepiece; by lining one end of the scale on the horizon, you can see how many marks “away” from the horizon the item is. A computer program takes into account the curvature of the earth and the height of our position as observers and calculates the distance to the item. With the ship moving up and down, it can be hard to hold one of the lines at the horizon, but Allan assures us we’ll get better with practice.
We’re using a toughened field computer to enter the data, but we just had a brief introduction today. We’ll also be recording some additional information on paper forms. I’ll tell you more about data entry another day.
We got back to port by about 1:30pm today, and a lot of scientists left to spend the night with their families. We also had a couple folks who came along just for the day today, so we dropped them off. We’ll also be gaining two more of the Big Eyes crew who are flying in from Maui today. Oh, and just so you know, we didn’t spot any marine debris or marine mammals in the short time we scanned today near Oahu.