A pair of Mark V Special Operator boats pulled into the dock at the Seaport Museum, following a tree-planting ceremony at the Walnut Street Dock.
Members of Special Boat Team 20 had been preparing for the ceremony when they heard the distress call.
"We heard a distress call on our mari-brand radio, quickly fired up our boat, got under way to respond, took us approximately 5 minutes," Senior Chief Charles Weaver of the U.S. Navy said.
With the Mark V's support vesssel, the Zodiak, in the water, a crew of 5 Navy rescuers spotted several accident victims.
"They assisted 3 victims in the water and I cross-decked one of my personnel over to a police boat to assist extracting a 4th person from the water," Weaver said.
Crew members of the Mark V then used its depth finder to conduct a bottom study of the river where it did detect what they thought might be the duck boat.
"We guided the police and Coast Guard to that location so that, hopefully, if it was in fact the boat involved the accident, they would quickly find it," Weaver said
While the crew was not expecting to be part of a rescue mission today, it is what the men are trained to do.
"I'm very fortunate that my men are very well adept and trained to react on very short notice to virtually any type of situation on the water; that training came in very handy today and I'm very pleased with them," Weaver said.
The Navy SEALs and Special Forces will be offering behind the scene tours of the Mark V's throughout the day Thursday. They'll return to Virginia Friday morning.