I received the following parking info in the confirmation email I received for my registration:
Parking & Transportation
Limited parking is available at the Hyatt Harborside hotel.
Hyatt self-parking rates are:
$7.00 per day
$15 overnight
Additional Parking is available at the Massport Parking Lot B next to the Hyatt Harborside:
These rates are:
$10 per day
$20 overnight
Water taxi transportation to the Hyatt Harborside dock is also available through the water taxi stands located on Rowes Wharf and Long Wharf in Boston.
Transportation from the Hyatt Harborside to the New England Aquarium will be provided for all scheduled Aquarium activities, including the Gala Dinner. This transportation will be provided by boat from the Hyatt Harborside dock.