It’s all about the weather

It’s 1:00 pm, the sky is clear, the sea is calm. It is time for you to conduct an underway CTD (uCTD). Take the probe and the protocol bring it astern, where the winch is. Load the slack on the tail end of the probe, to make it fall perfectly vertical. After 100 seconds you stop the winch and start the recovery. It will take about 10 minutes. 10 minutes you can stand out there enjoying the sun on your back and the beautiful deep blue ocean. Then the probe will come back in sight dancing along the sea surface until it is close to the ship. Now you need to concentrate for a minute to get it back on board without it hitting the ship. Under these conditions it’s easy. After 15 minutes in the sun it’s all done. Conducting measurements can be enjoyable.

Complete and successful uCTD measurement in the sun.
Photo: Paul Witting, Daniel Rudloff
Starring: Nils Niebaum

Now we jump in time, it’s 1:00 am in the middle of the night. Everyone is asleep, except you. It’s again your watch, time for you to do a uCTD profile. The sea is as far from calm as the sky is from clear and of course it is raining. Even worse is the wind, 22 m/s (roughly 80 km/h). Going outside is not as uncomfortable as you first thought but being astern where there is no shelter from the wind anymore, you just want to get it done. Load the slack on the tail, throw it overboard, let it fall for 100 seconds. By now you are soaking wet. If not from the rain than maybe from the sea spray or the waves hitting the ship spilling sea water on deck. But again, the recovery will take 10 minutes. By the time it’s all done, your shoes are filled with water, you’re freezing and just happy you can go inside again. Conducting measurements can be uncomfortable. Good we have a sauna on board.

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