In the ocean all bodies are affected by high currents but the unique dynamics and design of the Fiobuoy means it works differently to normal floats and acoustic releases.
Provided your Fiobuoy has an excess of rope for your deployment depth, your Fiobuoy will surface. Once surfaced, for the period of time it takes for the remaining line to unwind from the spool, you have time to retrieve it. This is because during this time the Fiobuoy is effectively an untethered free-floating body which will not be dragged under by currents (unless they are extremely strong).
Also the Fiobuoy’s unique ‘unwinding’ principle means it doesn’t need to drag or pull the full length of line through the water column. This combined with the fact that at the time of ‘unwinding’ the Fiobuoy doesn’t lift anything but its own weight means it rises to the surface easily. Click here to see this unique unwinding principle in the Fiobuoy in Operation movie.