So today our team bounced some ideas around to see if we could find a solution to Silbo's predicament. For the past few months, Silbo has been faced with a strong current ranging from North North-West to North North-East that has slowed us to half of the speed we have flown in the past. One idea that we had stemmed from an event that happened last week, when Silbo had an error that caused him to only dive to 600m. When he surfaced he reported that the currents were closer to what the model is telling us: flow to the south west! So the initial idea thrown around was only having Silbo dive 500m, however this would cause the pump to move twice as often, bleeding the battery. Another option suggested by Ben from TWR, is to have Silbo dive to a depth we feel would have favorable currents, and maintain that depth and have that favorable current push us for a few hours.
Antonio and I suggested that if we try this 'hover' strategy, we should try for 200m. It seems that the currents towards the surface may be closer to what the models are telling us, so we chose a depth that wouldn't take us too far into the unfavorable current. Another aspect to take into account is that we want to stay out of the productive surface waters. From our experience and the word of others, the rule of thumb seems to be that barnacles stick to waters >15˚C. As seen in the temperature time series above from Silbo, 200m keeps us in waters that are roughly 12˚C. We may not get to this test tomorrow, but I will update you guys on our progress over the weekend.
Down south, Challenger continues to shoot through South African waters on her way towards open ocean.
Tomorrow, we may move the way point more to the north to take better advantage of this northward current we are seeing and ride it out for a few years. It seems the counter clock wise spinning eddy is slowly moving off shore, so we are trying to bring Challenger towards the outer edge to avoid the possibility of being dragged south when we reach the other side of the eddy.
Force Wind Sea & Honor