Perhaps our houseboat trips to Lake Powell in July might offer some good ideas. First thing we do is scout out the different shade spots on the boat and which are most effective at different sun angles. We take as many old bracket towels as we have coolers and dip them every so often in the water and place over the coolers as evaporators. Extends the life of the ice by a factor of two. Requires a bit of fussing, but when it's 106 °, the effort is worth it