I'm willing to bet that at some point or other we have all pondered if self tanning can prevent the skin from tanning naturally? Applying a light layer of self tan before jetting off to somewhere sunny has becomes somewhat of a ritual for many (myself included), if you have ever worried that by doing so you have minimised your chances of achieving a natural tan let me put your mind at ease.
Self tanner typically does not contain SPF of any type therefore it does not protect the skin full stop, the sun rays can still penetrate and damage the skin regardless to how many coats you apply. All self tanning does is artificially tint the skin, when the tanner washes or fades off your natural skin tone will be revealed once more. Think of it like this, you apply a SPF free foundation on a sunny day, does your skin still tan or burn as normal? Yes - well self tanning is the exact same, it will not shield you from the sun full stop. If you burn or tan the process will be identical and this is why you should always apply SPF over self tanner to protect the skin.
While we are on the topic of the sun and self tanning I do want to mention that the chlorine in the pool and the salt in the sea will strip and fade any tanning product (the same applies with darker hair colours too), so you may want to pack a gradual tanner or an instant tanning product. I personally recommend packing an instant tanner as you can also even up any tan lines or in my case match the bottom of my legs to the rest of my body. There has to be a scientific reason as to why my the bottom of my legs never tan?
So to answer the question, once and for all - yes you can still achieve a natural tan when wearing self tanner.