At-Sea Navigation, Inc., 534 East Putnum Avenue, Greenwich, Conn., has applied to the Maritime Administration for a Title XI guarantee to aid in financing the construction of two oceangoing tug-barge units for transportation and incineration of chemical wastes off the Eastern Coast of the United States.

The 3,360-bhp diesel tugs would be 295 gross tons each, and the barges 7,000 gross tons each. A builder has not yet been proposed, but the applicant has indicated it would seek delivery in March 1983.

If approved, the Title XI guarantee would cover $47,435,500, or up to 87 1/2 percent of the total estimated cost of $54,212,000 for the two tug/barge units.