Sail boats and power boats are the two main types of pleasure craft.
In regards to the specific question, excluding ships, there are a varying sizes of fishing boats from quite big to two man boats. There are many ferries, canoes, pleasure boats and tugs.
Go to the docks and there will be two kinds of boats.
The two main kinds are discrete and continuous.
there are far more than two main kinds of submarines. The only two sections I can think of to separate them are fast attack and Boomers or Ballistic Missle.
kinetic and potential
consumers and producers.
indentured and chattel .|.
quiet and explosive
The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps.
The action verb and the linking verb.
Eucalyptus and Australian acacia
The two main kinds of cheating is on the Internet (no physical contact) but suggestive matter between the two individuals which is still considered cheating and the second type of cheating is physical cheating where the two people can meet somewhere secretly and have a sexual relationship.