The Boston Harbor Island Alliance announced that there will be free ferry rides to Georges and Spectacle Islands today until 5 p.m.

The free ferries will run on a special schedule. Those interested in hopping a free ride should pick a time block and island.

Due to high demand, all tickets will be issued on a first-come, first-served basis and have a specific return time, according to the Harbor Island Alliance website.

Groups are limited to five, and there are no advance reservations.