Ocean Rubbish:

Is it feasible to have two tanker style ships sail up to one hundred metres apart, and tow a net between them?  Periodically they stop, clear the net, and continue.  Any rubbish collected is then sorted and reprocessing procedures are started by persons employed to do such.  Studies could be about the origin and aging/disintegration of the rubbish.  Once back on land, the sorted rubbish is inserted into local waste streams.  If there are two or more 'pairs', a 'factory' ship might be added to assist in the sorting/reprocessing.

Notice should be made of possible removal of schools of fish, and other assorted ocean life.  Biologists could be among the persons employed.  For the possibly long voyages the accommodation might be 'motel' style.

Depending upon the fuel requirements, some of the rubbish could be reprocessed on board for fuel - in other words, burnt (bearing in mind possible inconvenient by-products).