Can you program a delay time of say 5-6 seconds into the built in failsafes?
If not, then they may be of limited use. Most failsafes are aimed at aircraft modellers, where you are transmitting, erm, through the air. With submarines, we are transmitting through a much more viscous medium, thus radio glitches are the order of the day. If the failsafes trigger immediately you can guess what effect this will have on your submarine.
Thus failsafes designed for submarine use tend to have a failsafe that kicks in after a few seconds, long enough to ignore glitches, but trigger when a major signal failure occurs.
Andy