Hydrophone drama

Copyright M.Fumagalli/HEPCA

It was a day like most others on the Red Sea Dolphin Project. The observers were looking for fins from the sundeck, the lab operator was inputting lots of birds in the database and the acoustics operator was trying to catch some whistles with our nicely working hydrophone. At that point the familiar tone of “Sighting! Sighting!” was sounding through the radios. More than 150 pantropical spotted dolphins (Stenella attenuata) were surrounding the boat! Everyone was rushing to their places – and Ian, one of the interns, made is way to the back of the boat, where the hydrophone is let in the water. After a few minutes of extensive picture taking, Marina noticed some turbulence in front of the boat and we were hearing an insistent demand of “CUT THE ENGINE!!” through the radio. The boat was moving backwards! Which, in a normal case is not any kind of problem, but with a hydrophone directly next to the propeller, can be an expensive maneuver. While the whole boat started to shout, the majority of people were gathering at a cable clearly stuck under the boat. Great job!

In a fraction of a second our research team was in the water, 3 languages were spoken at once and everybody tried to do their part to minimize the damage. The intact lower part of the hydrophone, which luckily was not cut and sent to Davy Jones’s Locker, was hauled back on board, the research and diving crew entangled the pieces of cable around the propeller and after an hour everything was back on the ship. Not in one piece, but back on the ship.

Was that the end of our acoustic exploration of the red sea?

We wouldn’t be such a neatly working team, if we would just accept a torn to shreds hydrophone. So we examined the damage closely, discussed with now a bit calmed down minds and came up with a plan to repair it right on the spot. Without proper equipment. On a boat.

The end of the story? Five hours in a sauna (called our “Lab”), pieces of cable everywhere, one replaced fuse, 50m of Kevlar reinforced cable lost and, most important of all, a once again nicely working hydrophone. Happy end. Let the recording begin…

Johannes (HEPCA intern)

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