That's why we try to Unpave the Way for Hummingbirds. To conserve energy, hawks search out thermals and updrafts, which are columns of rising air that birds can circle on to gain altitude. Hawks spread their wings and tail wide to increase the surface area so they rise faster. As soon as they locate another thermal or updraft, the birds start rising again. However, there are virtually no thermals or updrafts over water.
Downdrafts can actually drive hawks lower and lower until they fall into the water.
Because it just isn't worth the energy they'd need to fly over a large body of water, hawks don't choose those routes and you won't see them there. Match each species to its food. Match each to its range map. Broad-wings are reluctant to fly over water. Ones migrating south that end up in Florida rather than Mexico can either backtrack over a thousand miles or just stay put.