Fly into Cancun and rent a car for the drive to Akumal. There are also buses and shuttles with some hotels or dive shops offering free shuttles. Akumal is approximately a 2 hour drive from Cancun.
Unless you plan on just staying in Akumal, you will need a rental car to get around. The closest sights are at least a 20 minute drive. However, if you're not comfortable driving in a foreign country, there are plenty of taxis to take you wherever you need to go.
There are also colectivos, a local 15-passenger van service that runs between Playa del Carmen and Tulum. They're cheap (15 pesos), and usually full, but run very frequently. This is the preferred local way of getting around.
Akumal has a beautiful bay with a wide white sand beach, wonderfully warm blue-green water and great snorkeling. Cute little town with several restaurants.
With the destruction of hurricane Wilma, the reefs near Akumal were damaged. However, a snorkeling trip is still very worth the time and expense. There are three options for snorkeling:
Since coral dies on human contact, you should avoid touching coral at all costs. It is also illegal to touch the wildlife, such as the sea turtles. As of January 2006, there were five sea turtles living in the bay.
A few small shops in town. No real shopping to speak of.
There are also other restaurants in North Akumal (near Half Moon Bay):
In nearby Chemuyil:
Most restaurants serve beer. Lol Ha and La Buena Vida have full bar.