A major auction of offshore wind leases off New York and New Jersey will for the first time include an incentive to use US vessels.

The federal government has announced plans to auction off some 480,000 acres (194,000 hectares) of an area called New York Bight, with 7 GW of offshore wind capacity.

The leases are the first to have supply chain-related local content requirements that include investments in US vessels, said Charlie Papavizas, a Washington DC-based maritime lawyer at Winston & Strawn.

In the fast-growing offshore wind sector, the Jones Act already calls for vessels that are built at a domestic yard, that fly the US flag and that are crewed and controlled by Americans for many activities.

But US law does not extend those requirements to all offshore wind activity on the Outer Continental Shelf.

The terms of the new auction stop short of adding new requirements for Jones Act-qualified vessels, but they do ask companies that win the lease auctions to submit a statement of goals to make supply chain improvements, including investments in "installation, downpipe, survey and other vessels".

"It's a good indicator that vessels are important, but it's not a mandate," Papavizas told TradeWinds.

The announcement of the lease auction by US and state officials is the latest big step in a ramp-up of offshore renewables development in waters off the country's north-east, where construction on the first major farm began last year and where US President Joe Biden wants 30 GW of capacity by 2030.