Turtles are cold blooded, more formally known as ectothermic, and require an external heat source in order to regulate their body temperature. Basking, or in human terms, sunbathing, is a method turtles use to regulate their body temperature and absorb light that is required for a healthy metabolism. When a turtle is basking, they heat up. When the turtle is warm enough or would like to cool down, they jump back into the water. A turtle that is adequately basking and controlling their internal temperature will have a healthy metabolism. Since metabolism is essential for all things life (activity level, digestion, bodily functions) it important your turtle has a place where they can bask. We (humans) do not need heat from external sources to control our body temperature. We are “warm blooded” and regulate our body internally (think about when your body heats up to counteract a chilly day or fight off a virus or cools down by sweating). The light that the sun produces also provides unseen but extremely important benefits to our turtle friends. This includes UVA and UVB light which is discussed in the light information page.
The best way to get a sense of this so-called “basking” is to either find a pond in nature with turtles or look it up said “nature” online. Nature shows us that logs and rocks that are accessible from water, dry, and allow for easy reentry (escape) into the water to be the perfect location to spot a turtle in the wild. Why is this? Simple! It is a great basking area. The essence of basking is relatively straight forward. Your turtle needs an area where they can soak up the sun (or lights, see the light information page.). They need to be able to dry off to more efficiently warm up their bodies. This area needs to be easily accessible. In nature, the top of a rock where the slope is relatively gentle or a log does the trick. Turtles are pretty vulnerable when out of the water (because they are slow) and need the basking area to be near the water, this is to jump back into the water if a predator is prowling nearby.