The differences between Similan Island and Phuket Island are as follows:

1. Different geographical attributes. Phuket is an island with provincial status, has a mature tourism system, a long history of scenic spot development, and receives a large number of tourists every year. Similan is a national park belonging to Phuket Province. It is an archipelago composed of multiple small islands, some of which have not yet been opened to the public to protect their original ecological environment.

2. The opening hours are different. The Similan Islands are open for limited hours each year, usually between November and April, while the rest of the year is for ecological conservation. In contrast, Phuket is open year-round, offering visitors a year-round travel experience.

3. Environmental protection is different. The Similan Islands have a higher environmental protection rate because it is closed to the public for nearly half of the year, which helps maintain its pristine natural environment. Phuket has received a large number of tourists for a long time, which has put great pressure on the environment.

4. The travel experience is different. The Similan Islands attract tourists with their clear waters, white sandy beaches and pristine nature. Here, tourists can experience a variety of water activities such as snorkeling and deep diving, and feel the charm of nature. Phuket, with its rich tourism resources and mature tourism system, provides tourists with a full range of tourism experiences, including beaches, water activities, shopping, food, etc.