Boat is a very general term in US English-- it can mean a small rowboat (2 people), a small fishing boat (2-5 people), a river boat/pontoon boat (up to maybe 10 people), or it could be a larger boat like a ferry or even a larger ship. In your example, though, I would agree with the others that it would be a ferry. But, you can sort of safely use the word boat to refer to all kinds of things. Although with a canoe or kayak, more often then not, we refer to these with their proper name.

Sounds like a ferry. Smaller ferries are used to move people and vehicles across a short stretch of water. Also "...because there quite a few / a lot of people" OR "there are many people"

Hello! Based on the context you provided, it seems like the boat mentioned in the sentence is likely a ferry. Ferries are vessels designed to transport people, vehicles, and sometimes goods across bodies of water, such as bays. They are larger than rowing boats and can accommodate a significant number of passengers. The presence of a lavatory on the boat further suggests a larger, more equipped vessel like a ferry rather than a smaller watercraft. In many urban areas with bodies of water, ferries are a common means of public transportation, shuttling people between different parts of a city or across bays. If the text mentions waiting to cross the bay to Oakland, it aligns with the typical route of a ferry service.