Many of Krabi's activities(such as kayaking) in the Andaman Sea are affected by tidal conditions. The sea level varies a lot at different times of the month. In most cases, you needn’t worry about this. It’s the tour operator’s job to organise the day around the tides and they will always make the best itinerary possible to take advantage of the conditions.
However, there are some instances where you would be better off knowing the tide times. If you are staying on a beach like Tubkaek or Nopparat Thara that is only swimmable at high tide. If you plan to do only a half day of kayaking in Ao Thalane, it is good to know the tides in advance so you can choose the morning or afternoon session – kayaking is best around mid-tide time and somewhat restricted during very high and low tide.
There are two high tides and two low tides each day in the Andaman Sea. The times and amplitude of the tides are influenced by the alignment of the sun and the moon. By the pattern of tides in the deep ocean and by the shape of the coastline and nearshore bathymetry. The pattern is high – low – high – low, with around 6 hours between high and low tide.
The tide swell varies from day to day throughout the month, with the strongest tides (the highest and lowest water levels) occurring around the time of the full and new moon, every 14 days or so.
Make sure to check the tide times on your trip date in order not to be surprised by tidal conditions.
Every day during the high tide period twice a month, from the 12th day of the waxing or the waning moon up to the 5th day of the new moon, the tide is at the peak of its ebb and flow, resulting in the phenomenon of a divided sea, the water gradually recedes to reveal the sand dune between Tup Island, Mo Island and Koh Kai (also known as Chicken Island). Enjoy observing the miracle of the divided sea until a large sand dune appears, linking up various islands in the area around 4 Islands.