True, although Alex Thomson might point out to you that alarms don't necessarily wake you up (remember when he crashed into Guadeloupe two years ago in the Route du Rhum ? ). Or a sleeping Olivier de Kersauson wrecking IDEC on the Pointe de Penmarc'h as he made his way home after beating the Transatlantic sail record in 2005 when his electrics tripped.
I agree with Howard that at 5 or 6 its it's not much of an issue, but at 25kts things happen pretty quickly.
