There are many different gameplays and scenarios in online fishing games, and the specific gameplays and rules may vary depending on the game platform and game version. Here are some common online fishing methods:

1. Ordinary field: The most basic fishing scene. Players need to use cannonballs to shoot different types of fish that appear on the screen. Each fish has a different score. The higher the shooting score, the richer the reward.
2. Boss Field: Similar to the normal field, but you need to defeat a huge BOSS fish. These boss fish usually have higher score values, but are also harder to defeat.
3. Competition Field: Multiple players are fishing in the same scene, trying to get the highest score within the specified time. The top few in the final ranking will receive additional rewards.
4. Special field: Some games may provide special scenes and gameplay, such as catching crabs, collecting shells, etc.
5. Multiplayer online: Some games also support multiplayer online play. Multiple players can fish together, complete tasks or defeat bosses together.
6. Fish invasion: There will be a large number of fish schools in the game. Players need to eliminate the fish schools as soon as possible to get higher scores and rewards.
   The above is just a part of the gameplay in the online fishing game, and the specific game rules and operation methods need to be understood according to the specific game.