The phrase "slow ferry" refers to a type of boat or ship that moves at a leisurely or relaxed pace when transporting people or goods across a body of water. Full definition
Recommended for large groups, avoiding slow ferry services and when travel arrangements do not coincide with our scheduled transfers. (cvvillas.com)
Growing up in Connecticut, we would drive four hours to Hyannis, Massachusetts, and take the Steamship Authority slow ferry (2 hours and 15 minutes) so we could bring the car across with lots of groceries, luggage, etc.. (mackenziehoran.com)
An unreliable but scheduled biweekly fast ferry (Kartini: 3 hours), plus a fortnightly slow ferry (6 - 7 hours) between Karimunjawa and Semarang. (travelfish.org)