Flat battery, or bad connection?
Regarding your Question of Seamanship about flat batteries (Feb 16), I’ve had a loose connection, and later a corroded connection, give the symptoms described. If there have been no warnings of a battery going bad, it seems unlikely they would fail so quickly, so check the terminals thoroughly first.
Even if the batteries have too little power to start the engine, they should produce enough power to run a simple GPS for short periods, or recharge a smart phone or a tablet, which should have all the information needed for a safe landfall. They could even provide enough power to run the lights for short periods when other vessels are spotted. It is going to be a long night of hand steering, however, unless you have windvane self-steering bolted onto the transom!
Chris Marchant