On the morning of 10/28/21 CALS was notified that Charles County was requesting assistance from any boats in the region to assist with a prolonged search for an overdue boater. CALS quickly rounded up a crew to staff Boat 10 and proceeded over to Cobb Island where the staging area was for incoming boats. Once on location Chief10B Stockton and Lt E. Richardson met with the Incident commander who briefed them on the events and assigned Boat 10 an area to search. Boat 10 being small and agile and capable of SONAR imaging was assigned a grid search of the shore line along Cobb Island (top to bottom) searching between piers and in water as shallow as 3 feet. Boat 10 spent 4.5 hrs doing a grid search with the side scan SONAR and was able to cover from the shoreline out approximately 300ft where the larger vessels could take over. CALS providers worked in a complex Incident command structure involving local, regional, national assets all searching for the missing boater. Sadly after 4.5 hrs of searching the conditions on the Potomac became too rough for Boat 10 and it had to return to port with no subject found. Larger vessels from Charles Co, Westmoreland Co (VA) remained on the rough water searching for several more hours.