Early this morning, we were approaching site 30 to recover two more instruments from the bottom of the ocean. We generally prefer night-time recovery because the instruments have a beacon that starts flashing a bright white light as it reaches the surface. This is an extremely efficient way of spotting the instrument. The instruments also have a reflect flag to help spot it during the day. However, things can get a bit tricky and tense at night if the beacon fails. This is what exactly happened, or so we thought! The instrument was supposed to rise to the surface at 03:15 hours. Those awake were all out on the deck trying to spot a floating instrument. We were lucky to have a bright full moon to help us. A couple of us were on the bridge with binoculars and night vision scopes staring into the horizon. On the other end, the OBS group was using their acoustics system to continuously range the instrument and determine how far it is from the ship. This helped us steer the ship so that we get closer to the instrument. As we started approaching the instrument, it surfaced and the beacon started flashing! That probably was the tensest moment we had, knowing that the instrument was somewhere out there in the darkness and out of our sight. It turned out that the instrument had extra weight stuck to it and thus slowed its ascent to the surface. Everyone had a sigh of relief when the instrument was finally on deck and secured!
The entire operation lasted about 6.5 hours, followed by a short 140-minute transit to the next station. We are now recovering about 4 stations, i.e. 8 instruments a day, as we steadily sail from the mid-Atlantic ridge towards West Africa.