The sargasso weed has been coming in strong for over a year now. It mainly collects in eastward facing bays, cuts and shoals due to the prevailing winds being ESE.
Every once in a while there is a localized effort to clean up a collection point around a boat ramp or similar area. This is very hard to accomplish and is labor intensive to boot.
We advise our charter guests to avoid the large patches both on the water and downwind at anchor. Two reasons for this; one to avoid clogging the raw water intakes on the yacht, and two for the smell in an anchorage.
As far as beaches go... if the beach faces at all to the east then stay away on this trip.