Offshore Fairness Act of 2005 - Amends the Submerged Lands Act to require the Secretary of the Interior to convey the interest of the United States in the expanded submerged land of the states of Louisiana, Mississippi, and Alabama, if the state involved demonstrates that specified conditions will be met. Numbers among such conditions the requirement that the state enact, and keep updated, laws or promulgate regulations equivalent to federal law or regulations regarding: (1) the environmental protection, safety, and operations of any operation pipeline in existence on the date of conveyance; and (2) valuation of oil, gas, or other mineral production from existing interests for royalty purposes.
Provides that if any existing federal oil and gas or other mineral lease or unit would be divided by the expanded seaward boundary of a state, the federal interest in the leased minerals underlying the portion of the lease or unit that lies within the expanded submerged boundary shall not be considered to be conveyed to the state until the date on which the lease or unit expires or is relinquished by the United States.