Well, it can’t be all fun and games- after returning from New Orleans we were back to the wire preparing for our Mexico cruise, and this time, my passport finally got put to use! The Gulf of Mexico is off the coast of Louisiana and while we do explore the Gulf, it is not considered Mexican or ‘International Waters.’ However, this cruise we traveled to the Bay of Campeche which is Mexican territory. Before the science party arrived, we spent a majority of our time adding the rest of our sensors to the CTD on our back deck. Every cruise involves different sensors, dependent on the scientists needs, and this cruise involved two aquatracka sensors and a CDOM sensor- which measures the “colored dissolved organic matter” within the water. Once the chief scientist arrived, we were able to add the last aquatrack sensor and finish wiring our c-cable with zip ties. Adding sensors to the bottom of the CTD is a lengthy process- especially considering that some may have to be moved around to fit all your necessary needs. It’s like the age long game of Tetris! We use hose clamps to rig the sensors to the bottom rosette platforms, then a cable plug (matching with the sensor) is run to the other end (channel) of the rosette pump. The cable prongs needs to be cleaned with contact cleaner, canned air and then silicon is added for extra lubrication and hold.
Due to the need of a 24 niskin bottle rossette- which is much large than a regular 12 bottle- it was neccessary to deploy our CTD off the back a-frame using our Dynacon Winch. Deployment off the back deck involves a process called tag-lining. Tag-lining is a simple- yet sometimes hard to maneuver- task that involves wrapping ropes on both ends of the rosette and loosely rigging the ropes around our two side cleats on aft deck. While our chief engineer uses our back deck winch to control the CTD, two people hold tightly onto the taglines and maneuver the CTD into the water as smoothly as possible. The tasks involves great tension and pull on the ropes to ensure the CTD does not crash into aft deck during descent. Once the CTD is in the water, two workers quickly pull the rope off the CTD and walk around our winch wire and off aft deck. While tag lining is a simple concept, it is also very dangerous as there are several “pinch points” where the CTD can potentially pin or slide into a worker. Like all things on a vessel, it is very important to always keep a watchful eye and ear for potential hazards. While bringing the CTD to surface, we use a hook called –for lack of better word- “a happy hooker”, which can be used to attach rope on both sides of the CTD to pull up for ascent. Due to the lack of visibility with the aft deck winch, a third worker is needed to signal our chief engineer when the CTD is at surface. During our daily CTD casts and tests, we noticed several anomalies coming from our temperature sensors during up-cast- which consequentially affected our salinity readings as well. After several modifications, we eventually changed out our temperature sensor, channel station and cable to ensure any possible issue was resolved. So far…so good.
Our biggest issue with this cruise was our constant need to terminate our CTD winch wire. Due to deep casts, and the inevitable spinning of our CTD underway- caused by currents, waves, winch spead and boat position, it was a reoccuring issue. We later found the issue of our winch wire, which needed to be replaced, compounded the issue greatly. Our technician and I were up all hours of the night and day terminating. A swivel device can easily fix this issue, but it is expensive and we do not always have all the equipment we need at sea- hence the need to always think on your feet. Terminating a winch wire is a long process (3-4 hours at a descent speed) and involves multiple layers of wire, plastic and internal termination. Despite the stress of constant termination, I learned a lot during the process and am happy for the new skill!
Unfortunately, despite the most valiant efforts, our CTD was lost to Neptune on our last day of sampling. Luckily, 99% of our CTDs were done and we returned in time for a lovely Cyclone- Seriously, someone pissed off the Sea Gods during this cruise. In the end, everyone landed safely and the spanish crew and our crew celebrated our stresses away the following evening on the docks. I am thankful to have met so many interesting, vibrant and unique individuals during the cruise!