I came across the same thing, I was using the flybuy camera and came across a bunch of ships just sitting there in the water - carrier, plenty of destroyers, cruisers and battleships I thought it weird they just sitting there in the middle of the ocean there was no land in sight so I tried to pinpoint where they were and directed the sub where I thought they might be took a while to find them but I thought this is worth it a taskforce just sitting ducks. Finally found them where as soon as I got with close range about 4000yds I dived, raised the scope and got within 2000yds then an island popped up out of nowhere.
The Island never showed up with flyby camera.