The island is geared towards diving tourists more than backpackers on a budget and offers both basic through luxury accommodation. There are hardly any currents and a wide selection of dive sites and dive shops, schools and resorts.
Ko Tao is a small island of approximately 21 km² and receives over a 100,000 visitors per year. To minimize your impact on the eco-system, notice that there are no garbage disposal facilities, so everything that can't be burned has to be taken away. Try to avoid plastic bags that are given out for every purchase you make. There is also no department to clean the roads or other public areas, so don't dump your waste on the open landscape. Water is scarce and electricity expensive, so don't waste them.
Historically Ko Tao was once a detention place for political prisoners similar to Ko Tarutao in Satun Province
Peak seasons in Ko Tao are from December to March and July to August. July/August is actually high season due to Northern Hemisphere summer and rain dominating most of the rest of the country. The Gulf of Thailand is on a separate weather system and is usually sunny, however regional instability - such as Typhoons in the South China Sea can provide daily bouts of rain. Monsoon is in Nov-Jan and can be constant rain for days at a time. It is a quite popular destination among Thais also, so it can be nearly fully booked on Thai holidays.
Note on safety: there is an ongoing Murder trial into two British tourists killed in 2014. This has uncovered the significant issues of drugs, police corruption, and mafia-style families which run the island. In addition several tourists have drowned while swimming in the last few years.
