You should have some square-rig experience and reliable leadership skills. Prior service on a smaller square-rigged vessel is usually required. Traditionally the 3 rd Mate has risen from the best of the ABs. Traditionally the candidate for third mate has risen from the best of the ABs. Most mates have prior command of larger sailing vessels.
Low pay is a hard reality of the Tall Ship world.
The salary is somewhat negotiable. A major carpentry project including new decks and other modifications to the ship is expected to begin soon. Work is expected to continue through late spring. Industry competitive salaries will be negotiated. You should also have a US Passport and personal health insurance.