It runs May through October, and is valid for weekdays only. It is a 2-for-1 ferry ticket coupon for up to 4 people (so, two people could go for the price of one, or eight people could go for the price of four, etc) – however, it is based on the availability to either Georges or Spectacle Islands (good for one island only).
The ferry boats are run by Boston Best Cruises, and schedules and fares are available online or you can call call 617-770-0040 to make a reservation. You must present the coupon at the ferry center at Long Wharf North on the Boston waterfront.
This pass (and discounts to many other area museums) is available on the library’s website, or you can contact the Reference Desk at 978-256-5521 x211 to reserve it.
Library museum passes are provided by the Chelmsford Friends of the Library.