That the Navy made a big mistake — and needs to correct it — should be beyond doubt.

Running aground a 9,600-ton guided missile cruiser in clearly marked waters, damaging a wide swath of valuable fringing coral reef, demands a willingness to contribute to the necessary repairs.

That damage caused by the grounding of the USS Port Royal off the Reef Runway on Feb. 5 was considerable, according to the state Department of Land and Natural Resources.

Roughly two acres of reef sustained the most serious scarring — large chunks of corals broken and crushed, pieces of rubble rolling with ocean swells, habitats for marine life destroyed. Initial surveys suggest up to 10 acres in all may be affected.

The Port Royal also left behind large amounts of bottom paint and 7,000 gallons of sewage.

The days are long gone when Hawai'i's coral reefs were taken for granted. Today, the reefs are rightly seen as a precious natural and economic resource, supporting tourism, recreation, fishing and endangered species like sea turtles, as well as protecting shorelines.

DLNR bears the responsibility of protecting the state's reef systems; and with the state's budget in shambles, it is right to insist that the Navy step up to help cover mitigation and restoration costs.

Those costs have yet to be determined, and long-term restoration needs are uncertain. But the Navy must move quickly to support the immediate work needed to clear away rubble and stabilize the reefs before the summer swells cause more damage. To its credit, the Navy is already moving ahead to get the necessary authorizations. In the wake of the crippled Port Royal, that's encouraging.