2, 4, & 6 seems under exposed, or is the sun behind the subject?
take a look at #6, it's hard to see details on the boat, and the banner on #6 is pretty distracting.
typically pictures dont' turn out too well if you're taking them while facing the sun. you'll be shooting the subject on their shadow side. if you have to shoot them from this angle, for portait, try to use some fill flash.
i wish i could see more details on the tree on 2&4, but maybe you're going with a ink block kindda look, but they just look kinnda generally dark.
#3, i wish i can see less of that wall and more of the sea, and have the sea more in focus. it's not that sharp at the moment
#1 is kindda really snap shotty, and lighting's not great