Voyage - Leg:OC 444
Voyage Dates:18-23 April, 2008
Chief Scientist(s):Chris German (German)
MS 24
Email:cgerman @whoi.edu
Cruise Objective:Trials of Sentry AUV
a) Test dive to >100m (USBL, DVL)
b) Science dives (LBL navigated) to depths in excess of 2000m
Science Activities:
Operations Area:
Continental Shelf & Slope, Sth of WHOI
39.0-40.0N 70.5-71.5W
Departure Port:Woods Hole, MA
Agent:Master R/V Ship Name
Scientist's Name
c/o WHOI
266 Woods Hole Rd.
Woods Hole, MA 02543

Contact: John Dyke
Phone: (508) 289-3770
Fax: (508) 457-2185
Arrival Port:Woods Hole, MA
Agent: Same as above
    Installed or Normally Carried Equipment:
12 & 3.5 kHz Bathymetry
CTD/Rosette, 24X10L - C, T, D, optical back-scatter (SeaPoint OBS preferred)
Pinger for wire use
MET Sensors - wind speed & direction, sea-state (sea-state -need to confirm with German) (BD 04/11)
GPS Navigation
    WHOI-Provided Equipment:
Air Tuggers (2) (Rigging Shop) (BD 04/11)
    Science Party-Provided Equipment:
USBL Navigation - Sentry Launch & Recovery; USBL Fish (IXSEA); LBL system (SENTRY)
Night Work Anticipated

We will need to use Ship's crane for SENTRY Launch and Recovery

Worst case scenario - we may need to use RIB boat in event of major system failure

Provisional Program:-

Day 1
Ship departs WHOI and begins transit to deep study area near 39.5N, 71.0W (Fig.1).

Day 2
Ship exits Vineyard Sound/Rhode Island Sound into Atlantic Ocean and, as soon as water depths and currents (as monitored from hull mounted ADCP) permit, we will conduct two or more shallow test dives with Sentry(~4100-15’N, ~7050-55’W?):
a) with a line attached, testing sensors, releases but no thrusters
b) with line removed to test basic vehicle manoeuvres

Day 3
With the preliminary shallow test dives complete we will continue to the deep work site where Uri ten Brink (USGS, Woods Hole) has previously mapped landslide features at the base of the continental slope in 2400-2600m that extend ca.45km E-W and 30km N-S with scarp heights of 60-120m.

Day 4
Ship arrives in deep work area and deploys 2 x LBL transponders at 4km separation.
This will provide LBL coverage for deep Sentry operations over an area shown by red ellipse in Fig.1 – precise setting to be determined (Chris/Uri/Dana/others).

Day 5-6
a) Ultimate goal is to prove Sentry’s ability to obtain a scientifically interesting bathymetric map from within this area using the Reson multibeam system together with co-registered oceanographic and magnetic sensor data.

b) Whenever Sentry is not in water, shiptime will be used for either (i) collecting 3.5kHz and 12kHz echo-sounding data across the sedimentary features under investigation (ten Brink) or (ii) testing the USBL system from IXSEA in stand-alone mode.

Day 6
If time and successes in all primary goals permit, we will attempt 1-2 Sentry lines up and across the continental shelf between 200m and 2500m depth, navigated by IXSEA USBL system.

Break off operations at deep site, commence transit

Return to WHOI
Other Notes:
SSSG Tech:sssg@ oceanus.whoi.edu
Check List:Required?Comments
US Customs FormNo
Diplomatic ClearanceNo
Isotope Use ApprovalNo
SCUBA DivingNo

Last Modified: 04/11/2008