There is a prof. at Texas A&M that is using satellite technology to identify the larger areas of floating sargassum that will eventually arrive on someone's shores.
Here is a link http://seas-forecast.com/
Click on the Forcasts box to see the areas of heavy accumulation and, in general, where the stuff is likely to hit due to the WNW rotation of currents.

Unfortunately it appears he passed away last week.

The website has some Caribbean forecasts since he died in early September so it appears his students are continuing to monitor satellite imagery and maintain the site. Time will tell if and how long this will continue.

You would think that there would be quite a bit of research tracking the stuff now that it is such a big deal and has such financial implications for tourist areas in the Gulf and Carib.

Since he was a professor at Texas A&M at Galveston I'm sure the project will continue without him. Some of the photos of seaweed accumulation on Gulf beaches in Texas make the worst conditions in St Martin look puny.