….. to be here!
We’ve have spent the last few days, on and off due to the weather, recovering instruments from the seabed.
The plan is for these to have their multi-types of data downloaded, and then for them to be reset and redeployed along another profile.
Given their rather large antenna arms, there is a fine balance between adding sufficient flotation to ensure that the instruments rise at an appropriate speed vs attaching too much ballast such that the speed they rise causes the arms to bend or even rip off entirely.
So we have a Goldilocks – not too much and not too little.
The just right results is a slower rise rate than is normally the case for platforms purely listening to seismic signals, and in deep water this can mean we have to wait several hours for each to surface once it is released.
But progress may be slow, but it is steady and, one after one, up they come.
The first challenge is to spot each platform once it has surfaced – even with binoculars that can be quite difficult.
The next challenge is to get close enough to catch its stray line, without bending or breaking the antenna arms or sucking them into the vessel’s propulsion.
Once caught …..
….. it is then a case of untangling the strayline and feeding it through the arms, and then clipping on a tag line using a very long pole and a “sea catch” so that the platform can be plucked from the water by the crane ……
…… and up she comes …
… thankfully with arms in tact.
And once inboard, it is landed on its next ballast weight, and its arm removed to make it stowable until it is time to ready it to be deployed again.
A download of the data recorded by this one, revealed that it also recorded the Moroccan earthquake.
And sometimes these platforms are on the seabed long enough to be viewed as a good home …… and new residents move in ….. this little chap didn’t anticipate a slow ride to the surface when he moved in.
We have also picked up a hitchhiking racing pigeon who should have been on its race way back to the UK from the Channel islands. Seems to have turned left instead of right, and now will be taking the longer, scenic, scientific route home.
OBS'ing at sea 