Assuming the newspaper article is correct and the Sargasso seaweed does happen again this year, I don't know that there's any way to know it's duration. We typically travel in mid to late April and that one bad year was the first time in about 40+ years of annual trips we ever experienced seaweed to that magnitude, and my understanding is the vast majority of the mid-Caribbean was effected to one degree or another that year.. I'm sure someone more knowledgeable than I will hopefully be able to answer that question accurately.