Introduction

Diary

Participants

 

R/V Pelagia Cruise HERMIONE /CoralFISH
	Diary overview
Thursday, 29 October
Following yesterday's adventure with the runaway BOBO lander, a multibeam survey was carried out during the night in the upper canyon area to see if we could find a more suitable landing site for re- deploying the lander. Free-falling landers like BOBO and ALBEX usually do not land exactly below the place where they are released from the ship, but under influence of currents they will drift off a few tens of meters away from the projected landing spot. How far and in what direction is hard to predict if we don't know these currents beforehand. When a reasonably flat piece of canyon bed had been selected, wide and long enough for a safe landing, the lander was lowered into the water and released shortly after 8 o'clock in the morning. Triangular ranging later confirmed that BOBO had safely landed on the canyon floor 1500 m below us.   Next on the program was deployment of a second BOBO lander at 4000 m water depth in the lower end of the canyon, more than 80 miles to the southeast. Steaming against the wind and current, we would need most of the day to get there. A lot of time, spent in preparing the BOBO lander for deployment and a variety of other activities. Mostly indoors, because the grey autumnal weather with rain and gushes of salt spray splashing over the decks was not really inviting to stay outdoors very long. What can you do on a ship during a long rainy day? Why not, a helicopter drill! Very useful to know what you have to do in the eventual case when someone has to be evacuated from the ship by helicopter. Inge was appointed as volunteer to be strapped on a stretcher. When no helicopter appeared to take her away, she was eventually released. To our luck, because in the evening Inge showed us a very nice compilation of the best coral & fish video and photo stills.   At 8 o'clock in the evening, after a short multibeam inspection of the landing site, the second BOBO lander was launched in the lower canyon. Its descent to the sea bottom would take approximately 1.5 hour, and only late in the evening ranging of its position could start. Unfortunately the wind had picked up in force, and waves were splashing against the hull of the ship. No matter how intensely we listened, no response was heard from our lander deep down, only a nervous whispering of water…Unable to communicate with the lander through the noisy water, we could only hope that it arrived safely and is now collecting data for us. We departed from the Whittard Canyon shortly before midnight, heading south to our next destination.   The Whittard Canyon in 3D with the positions of the BOBO landers. . Henko de Stigter