Final answer:
The correct entry method for an unexpected fall into water is Emergency Entry, which is necessary for fast response to prevent drowning.
Step-by-step explanation:
The entry method suitable for an unexpected fall into the water is known as Emergency Entry. This type of entry is critical when someone falls into the water without intending to, as it emphasizes the importance of a quick response to prevent drowning. Unlike planned entries into a pool or during a swim, an emergency entry does not follow a set technique due to the spontaneous nature of the situation.