"undulating sea" is grammatically correct and usable in written English.
For example, you could use it in a sentence like this: "We watched in awe as the undulating sea crashed against the rocky shoreline."
There are no palm trees here at the shore, but you do have the dunes with their beautifully undulating sea grasses.
The late evening sun shone down over the gently undulating sea and for a moment, just a moment, it felt like paradise.
An undulating sea of black suits filled the men's section of the synagogue.
Mr. Chihuly's shimmering yellow basket gently cradles miniature versions of itself, while Mr. Lipofsky's examples from his GA Series recall colorful, undulating sea slugs.
That's the line that Taeyang, of the South Korean boy band Big Bang, crooned to an undulating sea of light-stick wielding fans at the Prudential Center, in Newark, the other night.
Sprawled across 80percentt of the landscape, the undulating sea of sand hides medieval oasis cities, teeming market towns and acres upon acres of prehistoric cave paintings at Tassili Oua-n-Ahaggar.
Almost as good is a crisp-skinned fillet of sea trout (£14) adrift on an undulating sea-bed of samphire and lightly creamy lentils.
When you look out in awe over the burning spacecraft of Mass Effect, the hazy, fecund forests of Far Cry, the undulating wireframe seas of Mercenary don't wonder, is it art?
The airbeast obeyed, cilia along its flanks undulating like a sea of grass in the wind — a host of tiny oars rowing backward, slowing the Leviathan almost to a halt.
The course, shortened by 90 miles in anticipation of light winds, goes west down the Channel and then north to an exclusion zone off north Cornwall where heavy electricity cables lie undulating on the sea bed and then back south to Wolf Rock and past the Lizard before heading west up the Channel to the Owers Light off Selsey Bill and the dive south to the finish line at Dieppe.
Kevin would snort a fat line at 1 PM, and by the time he got back to his desk at a digital marketing agency, he'd spent the last hour "floating weightless atop an undulating green sea" at the park down the road.
