I'm one of those seemingly rare players who always does fleets when they pop, and up until this update I was constantly frustrated with fleets de-spawning just as I get to them due to the fact they were so near the edge of the map, and by the time I had stocked up it had gone.
However finally I'm able to do them on a consistent basis, the new locations I feel are perfect, they offer the same environmental obstacles with islands and rocks and are now so much easier to get to with them pretty much being near wherever you spawn. It also creates the added threat of player ships as you'll have a much greater chance of encountering them with the locations central rather than right at the edge of the map.
I do, however still have a couple things I feel need changed. I still feel there needs to be a bigger loot payout as currently after sinking the captain you get roughly no more than 10k gold, and when you can do a regular fort in the same time without the drain of resources, no wonder I'm able to solo them without any player ships even attempting the challenge. I also feel there needs to be greater availability of resources as when you do a fort, all the resources you need (fruit) are supplied for you with multiple barrels, however this isn't the case with fleets, as although you will occasionally see barrels or a ship wreck, you rarely have enough time to supply between waves. I suggest that each ghost ship sank drops a fruit, cannon ball, and wood crate each, with varying amounts in each, making it easier to supply throughout.
Overall this new update is a definite improvement to the previous build however more needs to added in order to get more players doing them so they become the enthralling ship battles they should be.