Watch Leader Duty List
1). CTD Prep: ~20 minutes before station arrival, rally the watch for CTD prep. If weather-decks are secured, wait until arrival for station.
- Check if the ISUS battery needs to be changed (every 6 full casts)
- Rig the bottles open, tighten breather valves, turn spigots off pins
- Pull both CTD pump hoses
- Uncap the PAR and SCCOOBOP (if mounted)
- Rinse the transmissometer with RBS
- secure the 3 tag lines around the upper ring and cleat;
- untie the bottom eye-bolt lines.
- unbungie the CTD wire and slacken the cleated CTD block tag-line, if secured during net tows.
- Pull CTD wire-slack to outboard side of the block, careful not to snag anything
2). Seasave Prep: ~8 minutes before station, power-up the CTD deck unit and start data acquisition without saving data to file. Connect the ISUS battery.
3). ~2 minutes before station arrival, record the deck pressure on the post-it.
4). For New Horizon: upon arrival (work vests are required for everyone participating in deck ops)
· Pull slack, being very careful to not let the CTD wire get caught under the CTD or any other snag point.
· Free up the cleated taglines so they can pay out, ask your tagline handlers if they are ready
· Check the hydro wire is able to pay-out around the J-frame stanchion.
· If the bridge/aft-control is ready, give the winch operator the upward “pinch” hand signal (bring it up slow). When the CTD is ~1m off deck, clench your fist to signal stop wire, then signal boom out by motioning outboard. The CTD should lift as the J-frame extends, lifting it over the rail. Monitor the tag-lines – they should not be slack but not be so tight that the CTD wire is angling inboard or aft. Once the CTD clears the rail, signal wire out by pointing down and instruct the tag-line handlers to let their lines slip. Once the CTD hits the water, have them remove their lines.
· Adjust the depth of the CTD to the yellow mark, the bottles should never break surface. Instruct the winch operator to “Zero there then take it DOWN to 10m”.
5). Go inside and start the 2min timer and open communications with the aft control. Start the Knudsen PDR and get a bottom depth while waiting – refer to the bottom depth cheat sheet for approximate depth.
6). Seasave Ops:
· Once two minutes are up, verify the pumps are ON, the sensors are giving good data, then bring the CTD back to the surface.
· In Seasave, stop data acquisition, then start acquisition but this time check the “Store on disk” box and name the file by clicking [Enter Output Data File Name] and using YYMM### designation where ### is the processing number.
· Fill out the header form – be sure to use the long version of line and sta
(ie 93.3 45.0, not 93.45). Add any comments that might be worth noting or effect data processing such as calm or rough weather or any startup glitches
(ie 93.3 45.0, not 93.45). Add any comments that might be worth noting or effect data processing such as calm or rough weather or any startup glitches
· Start acquisition, keep the CTD at surface ~1 minute, double-check all the sensors are reading reasonable values (mainly T, S, O2, pump)
· Switch the winch/weather screen to winch readout so the winch operator can monitor CTD depth directly.
- Send it down to terminal depth, usually 515m depth-permitting. Once you determine the chl max, select the appropriate type (I, II, III or mod III) Console Ops sheet. Refer to the “cheat sheet” for accessing cast type and expected bottom depth (you should verify expected bottom depth BEFORE sending the CTD down). Use the altimeter to adjust the CTD depth on cast near-bottom. Never get closer than 5m during calm weather or 10m during rough weather.
- Another precaution, when filling out filename field on console ops, verify data logging in the lower right corner of Seasave. It should read “saving data to disk” and list the filename.
- Check with ancillary projects or prodo person for bottle depth requests and edit the desired bottle depth as needed.
- Upon arrival to the desired depth, fill out the console ops record; the CTD should sit at that depth a minimum 20secs to flush properly. If the bottle depth is off by more than 3m in calm weather or 5m in rough weather, have the winch operator adjust the depth. This criteria is less flexible during prodo casts where the median depth should be the target depth.
- Keep track of the marker and bottle trip counts – they should match each other and the console ops. Sending the CTD back down to collect water is a good idea if you find you missed a bottle trip. Just note it and adjust the sampling.
- At ~50m, ask a watch-stander to rig the hooker lines if not already done
- Once the last bottle is tripped, recover the CTD, leaving Seasave logging.
7). CTD recovery:
- Have the winch operator lift the upper CTD ring out of the water so tag-line handlers can hook it. Verify the right number of bottles are still open.
- After the lines wrapped around the cleats and line-handlers are ready, signal wire up and when higher than the rail, signal inboard. The center tagline should be attached as the CTD approaches the rail and wrapped around the cleat quickly.
- This is the most important part of deck ops since the CTD weighs ~1500lbs. Tag lines should be snug but allow the CTD to center over the eyebolts – the inboard line-handler is the key and should be strong enough to hold the CTD during ship rolls. During rough weather, be patient – let the roll assist in centering the CTD, the tag-line handlers should not allow the lines to slacken such that the CTD can accelerate in any direction. Once centered, tighten all tag-lines and signal the CTD lowered slowly (downward “pinch”). If the CTD misses the center, have it lifted a few inches, adjust by slacking the outboard tagline (usual culprit) and lower.
- The tag-line handlers should cleat-off the taglines and secure the bottom eyebolt lines. Once the bottom is secured, you can release the upper lines (unless really rough).
- The Fisheries tech should start pulling 15m of slack in the CTD wire while you go inside.
- Record the final deck pressure on the console ops, stop data acquisition in Seasave, hit <Ctrl><Alt>B (or V) to immediately back the data up and generate the sample log base file; turn off the deck unit.
- Unplug the ISUS battery immediately and protect with dummy plugs
- Load the Sample Log in CESL, verify the cast information looks good, check/change the O2 case #, salt case #, nut rack color.
- Draw O2s
8). Watch leaders are responsible for sample-drawing correctness and completion so be sure to instruct sample drawers to check CESL for sample types and bottle #s. Watch leaders should verify all samples are drawn including phyto. When stations come quickly, double-check with LTER that all their samples are drawn before draining the bottles and re-rigging for next station. If the next station is within 1 hour, you do not need to uncock the bottles (unless there is a risk of contamination).
9). CTD post-cast maintenance (if next station is more than 1 hour away)
- Connect the pump tubes and flush the system with DI or MilliQ for several seconds. Check the water is flowing out the other end without difficultly. Sometimes jellies get sucked into the plumbing and can restrict flow.
- Cap the PAR, uncock any open bottles, reset the carousel arms and flush with fresh water (hose).
10). Print the 3 main plot to PDF then print hardcopies (from Acrobat). Print the .mrk and .prn files; fill out a tab label; bind the console ops, plots 1-3, mrk, prn (in that order) into the CTD binder. Reset Seasave onscreen plot labels to the next station and leave a post-it updated with Line Sta Proc#.
NOAA ship operations are different since Fisheries techs are watch leaders on NOAA ships but we still direct CTD deployments; hard-hats and work vests are required for everyone participating in deck ops
- CTD prep and Seasave steps are the same but deployment differs
- Untie the CTD if taglines are fastened;
- Secure your tethers-safety belts before dropping the safety line
- Take up any slack in the CTD wire
- Record CTD deck pressure
- As the winch operator for bridge authorization
- Deploy the CTD when given the OK by Bridge/Aft Control
- CTD soak, depth finding etc are similar to New Horizon
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