This afternoon I took my freshly repaired Vision+ to Ft. Armistead Park for a few flights. Temps in the 50s, a little breezy but nothing she can't handle. Away I go! About 5 minutes into the flight I am heading towards Ft. Carroll about 4000'+ out @ 200' altitude. I'm almost to the island fort when all of a sudden the battery klaxon sounds. Look down & the battery is @ 68%. I was only at about half forward throttle but I let off the stick thinking it will settle down under reduced load at hover. No dice & now I notice the battery is showing 0%! Uh oh! I know I will never make it back to shore so instead I head straight for the fort, panning down to make sure I am over the island. I centered up as best I could and watched the FPV feed as she began auto-landing. As altitude drops my FPV & telemetry eventually drop out. I'm thinking "Please do NOT attempt a RTH now!" I pop open the Flytrex app & am relieved to see she is coming straight down with no forward speed. At least I know she settled on land instead of getting lost forever in the Bay. Unfortunately she is on a deserted island fortress 4500' out in the middle of the Bay, its getting late, & I don't have a boat! I noticed a pickup with an empty boat trailer in the lot and waited around hoping for a miracle. I kept checking the Flytrex feed. She was **** near dead-center on the fort & she remained powered on for almost an hour with the Flytrex dutifully reporting her status. Battery was @ 9.07 volts last time I noticed. Not too long thereafter a small boat came in towards the launch piloted by a chap named John. I explained what had happened and asked if I could trouble him for a ferry to the Fort. He invited me on board & away we went. Once at the fort I just followed the Flytrex "Last Seen" straight to the bird. She had settled down in some vines & landed on her top. No damage....whew! I tried to offer John money for his trouble but he would have none of it so I left him with a huge "Thank you!" I think I'll take this opportunity to replace my P2 batteries as they are around 20 months old & seriously cutting up! I can hardly believe my good fortune in having the sense to head for the island and managing to recover the aircraft. I never want to have one of these things without a Flytrex installed! It's money well-spent!