The Two-Ocean Navy Act as America's Plan Z

Was the Two-Ocean Navy Act the US equivalent of Plan Z?

Broadly yes, though it expanded an already large fleet rather than building maritime power from near zero.

The Two-Ocean Navy Act is the closest American parallel to Plan Z. The comparison has limits because the United States already possessed a major navy and shipbuilding base. The Act enlarged established capacity, whereas Germany's plan sought to create a fleet able to catch much stronger maritime powers. It distinguishes expansion legislation for an existing navy from an aspirational catch-up programme.