4 boats, when we know there were three by Locke 2.0

I was just watching "the little prince" when I noticed something that didn't make sense. when Locke, Sawyer, Faraday all the people left behind go to their camp they find two boats on the shore. one with a Ajira water bottle in it. once I realized that there were two boats it go me thinking. we know that there were only three boats left on hydra island when the Ajira flight crashed. we know that frank and sun took the first and that Ben and Flock took the second.

so that would leave only one boat for Ilana and Bram to take to the main island. we also know that when Ben and Flocke showed up at the barracks the second boat was already there. hence Flocke saying "looks like were not the first to tie up here" ben says" thata be sun and Lapidius" so we know that two of the three boats are tied up at the barracks dock. we know that when Illana and Bram land on the island with Locke's Body that they are not at the Losti! es camp site. now this doesn't mean that they couldn't of gone there first than got back in the boat and rowed to another part of the island. so my question is this if we know that two of the three boats are at the docks and the last boat is Ilana's and Bram's how can there be TWO boats when Swayer, Locke, Juliet,...etc get to their camp during the flashes. there would have to be a fourth boat. which begs the question, WERE THE HELL DID THE FOURTH BOAT COME FROM. further we know that whoever was in that other boat shot at Locke and company, but in the incident there is no conversation between Bram, Illana saying something like "who were those people in the boat we were chasing, they shot one of our people and how did they just disappear". there wasn't any conversation even remotely like that. so now the question not only becomes were did the fourth boat come from and who was in that boat. could it be that Lcoke and company flashed to a different future, the alternate future! . I truly don't know but what bugs me is that there appears to! be four boats from hydra island when we know for a fact there were only three. please think, ponder (I know those are the same thing), come up with any explanation. love to hear it thanks.