>heat wave in the air
Too much. I think "in the air" could be assumed/implied by simply saying "heat waves".
>ocean still cool blue
"cool blue" is definately a cliche, in 'ku as well as poetry.
>rolled up jeans
I think you could reverse these last two lines with a little editing and make a solid 'ku.
rolled up jeans
wet with the ocean
or something like that...
I'm sure you can figure it out better for yourself how you would say it. Anyway, it's an idea...