You won't need a passport. Following are the ID requirements for U.S. citizens directly from HA's web site:
IMPORTANT: Guests arriving at embarkation without proper documentation may not join the voyage and will not be entitled to a refund.
The following documents are required for U.S. citizens:
Europe, Panama Canal/Coastal, Asia, South America or Prinsendam cruises:
A passport valid for the duration of the cruise and necessary visas; expired passports are not acceptable.
Alaska, Caribbean, Mexico, Hawaii, or New England:
1) A valid passport; ~or~
2) Picture identification issued by an official government agency AND an original or certified copy of birth certificate; ~or~
3) Picture identification issued by an official government agency AND a U.S. naturalization certificate.
Please note: Although passports are not required for some cruises, we highly recommend that you carry one while traveling.