True but the running on batteries thing is a bad idea because he still wastes a huge amount of fuel and if he begans this at 1800nm he most certainly boosts the odds that he wont make it in fact he may guarantee that he does not make it.Doing the battery is pretty much cutting your fuel in half it only works when very near a port like one days travel submerged at 1-2kts away from what others who have pulled it off have said.Never mind guess that's what your saying.
The best bet is to go slowly on the surface and not dive at all unless he must and only then for a short period and just keep going until he runs out of fuel or makes it.I bet he makes it with 5% easily if he takes the don't dive advice.Or a Japanese plane from Wake could spot him and sink him if his luck is really bad.
We should start a pool I say he can make it by going slow and avoiding unneeded diving/use of batteries and he'll sail into port without having to use the short range battery trick either.I put one case of Pabst on it.
