Their paddle-raft parked and voyage interrupted, three college buddies have asked the U.S. Coast Guard to prove their homemade craft is too unsafe to navigate the Mississippi River.

Legal briefs were filed in U.S. District Court for the Southern District of Mississippi Thursday to have Rear Adm. Joel R. Whitehead appear before a federal judge as soon as possible to show cause for giving the order to Coast Guard officials for the Lower Mississippi to pull the vessel off the river.

Libby Hendon, 24, Laura Mattingly, 25, and James Burkart, 24, who met while attending University of California-Santa Cruz, started their river journey July 21 from Burkart and Hendon’s hometown of Kansas City, Mo., as part of an art project. They were stopped Sept. 15 by boarding officers with the Coast Guard about 15 miles north of Vicksburg.

Made of household and commercial refuse and bicycle-powered, the raft was ordered off the water on the grounds it lacked proper registration. According to the rafters, Whitehead, commander for New Orleans-based 8th Coast Guard District, gave the orders upon being contacted by boarding officers.

In a letter to Vicksburg attorney Paul Kelly Loyacono, Whitehead confirmed he issued the order to terminate the voyage under federal laws dealing with water-borne recreational craft deemed unsafe. Whitehead cites it as having an “unsuitable design and configuration.”

In court filings, the plaintiffs argue Whitehead was not qualified to make the judgment because his determination was based on the reports of the boarding officials. Also, they note the timing of the order, which was made Sept. 21, six days after the three rafters first encountered Coast Guard officers.

Hendon, Mattingly and Burkart were on the river as part of a project entitled “Release Yourself onto the Water until it Tastes of Salt.” They said its goal was to experience the river through its people and locales. About a half-dozen strangers joined them on their excursion at various times in the six weeks the raft floated downriver.

Reached Friday, Loyacono said the trio was still in Vicksburg.