The District government said yesterday it would try to force the owners of the presidential yacht Williamsburg to pay seven years' back rent on 2.6 acres of Georgetown waterfront property over which the group has had control since first planning to launch a restaurant project there in 1977.

Although the ship owners have had "right of entry" to the property -- which essentially grants them all the rights of a tenant -- they have yet to sign a lease with the city. A proposed lease would allow the ship owners to use the land for $24,000 a year, which, according to real estate industry analysts, is less than one-tenth of its rental market value. The operator of the parking lot adjacent to the property, which is slightly smaller, paid the city rent of $400,000 last year.

D.C. Department of Administrative Services Director Jose Gutierrez, who is scheduled to become the mayor's director of policy next week, said the group should have been paying the $24,000 annual rent, which he said "seems kind of low," since it was given the right of entry in 1977.

Since then, the group has been paying only $750 a month to anchor the Williamsburg near the Blue Plains sewage treatment plant. The ship must be dismantled before it can clear the low-slung bridges of the Potomac River to reach Georgetown.

"The right of entry is revocable," Gutierrez said. "And we intend to ask for reimbursement for the time since the right of entry" went into effect.

But Stuart Long, one of the yacht's owners and a longtime supporter of Mayor Marion Barry, said he had never been told his group would be asked to make such a payment.

"We don't pay rent 'til there's a lease," Long said.

Harbour Parking Co. Inc. owner Jamie Lewis, whose lot is next door to the Williamsburg lot, said his lot had gross revenue of about $600,000 in 1984, and estimated that the city collects $60,000 a year in tax receipts from his operation.

"If the District would let me use the Williamsburg area for parking -- and it certainly would be utilized because of the demand in Georgetown -- we could eventually work ourselves up to $1 million to $1.5 million" in gross income, he said.

The other owners of the Williamsburg are Richard McCooey, owner of the 1789 restaurant in Georgetown, and cruise boat entrepreneur Willem Polak.

The property along the river at the foot of Georgetown has been the subject of continuing battles between residents of the area, who want it turned into a park, and the city leadership and developers, who favor development.

The $24,000-a-year lease plan is one facet of a deal under which the owners of Clyde's restaurant plan to buy the yacht and convert it into a 500-seat restaurant. But the Clyde's owners have said they won't buy the boat unless the city agrees to the lease.

The total cost of the Williamsburg project is now estimated at $10 million. That estimate covers the expense of dismantling the ship and transporting it to Norfolk for restoration; construction of a jetty in the river, and the building of both surface and underground parking.