Well, if they are delivering to the US East coast they will have 2 choices, go through the Roaring forties around South America, or go around the Cape of Storms in South Africa. Either of these are well known for heavy weather, large waves, high winds and some of the most ferocious storms on all the oceans of the world. Flying a GEV there will mean a very high loss rate, simply because no GEV works well in what is a moving version of the Grand Canyon, where you will have 50m plus changes in sea level in very short intervals. Flying above around 50m is getting you out of ground effect, and more into regular flight, and flying below 50m there in most cases will result in your engines getting a good slug of water dumped into the inlets. Rolls Royce does not guarantee that a Trent engine will still be in one piece with ingesting 200l of water as a slug, though they do warranty that it will run with 200l a minute being ingested as rain, but your blade erosion rates will be incredibly high, and with running in sea spray your engine lifetime will be massively reduced, expect a rebuild of each engine every 1000 hours at a minimum, from the salt spray erosion.