Runaway Home although he makes a few mistakes at the end which can be blamed on exhaustion.

The reason he is exhausted is that he has chosen to take a wholly inadequately provisioned open day boat on an eighty-mile cross-Channel voyage in January without charts, lights, adequate weather information and with only one other competent sailor on board. The fact that Giles becomes concussed in mid-Channel making this effectively a single-handed voyage is an unfortunate additional complication, but the exhaustion in general was entirely foreseeable.