im starting to think that if you have a logia fruit, and you get thrown over the ocean, and as long as they dont touch water...they can get back to shore...
-crocodile had the suna suna fruit and when he turned into sand,he could float in the air
-smoker, when he turns into smoke he floats
-ace floats as fire, as we all know heat rises
-eneru can probably shoot himself back to shore at the speed of light
-aojo kiji, well, he can freaking freeze the water, which i think is kinda cheat
now im getting the impression if you eat a logia type devil fruit, the sea is the least of your worries