FRV Alba Na Mara 1509A
Cruise summary report
|Ship name (ship code)||FRV Alba Na Mara (74NM)|
|Cruise period||2009-09-15 — 2009-09-24|
|Port of departure||Fraserburgh, United Kingdom|
|Port of return||Fraserburgh, United Kingdom|
To calibrate readings between a LISST 100X and Reson 7125, from the sediment plumes created behind towed objects on different sediment types.
The Diving Team and shore based personnel travelled to Lossiemouth on 14 September. The Diving Team launched the diving support boat Dignity and set up a shore base. The charter boat personnel set up and tested the Reson 7125 system onboard MV Solstice. Alba na Mara left Fraserburgh at 0500 BST on 15 September and arrived near Lossiemouth at 1030. All operations were carried out in inshore waters (20-25m) between Lossiemouth and Burghead until Sunday 20 September.
Alba na Mara and Solstice began practicing sampling manoeuvres with the roller clump at 1105. It was evident that the relatively narrow beam angle of the Reson in ~20 m of water meant that Solstice needed to be almost directly over the target plume to ensure interference free sampling. It was decided it would not be prudent to have Solstice sampling while holding position relative to the gear/plume if divers were operating the TUV. This would present a number of potential hazards for the divers in the TUV, firstly, the potential for collision with the vessel at the surface; and the prolonged exposure to high frequency noise at relatively close range to the Reson transducer. Therefore only sampling strategy "b" was attempted directly over the TUV. Three tows with the roller clump and one tow with the scallop dredge were completed that day. Meanwhile, the Diving Team conducted work-up dives and practiced emergency procedures.
Diving operations with the TUV and Reson system began on Wednesday 16 September, with sampling on the scallop dredge. The first TUV dive had to be aborted at the surface due to the new rudder's being unbalanced. This was rectified by cutting the leading edge back to near its original size. Two more TUV dives were undertaken and managed to position the LISST 100x in the plume at 5, 10, 2
|Chief scientist||Keith Summerbell (Marine Scotland Aberdeen Marine Laboratory)|
|Cruise report||(0.05 MB)|