Diving, both recreational and technical, has exhibited a huge upsurge in uptake throughout the globe, and so has the average age of the active diver. Thus assessing fitness to dive is imperative, and it has to be undertaken with a solid background knowledge of diving and diving medicine, the foibles of the diving environment and the sport, and the interplay between the diving environment, the medical conditions of the diver and the situations which may arise while diving. The first two editions of The Sports Diving Medical are widely considered to be the textbooks best guiding the field of assessment of fitness to dive, a field fraught with difficulties and pitfalls, especially for those not having received training in diving medicine or not being divers themselves. After two decades, we felt the need to rewrite the textbook from the ground up, keeping all the positive elements from the previous editions while adding all the advancements and evidence base in internal medicine & diving medicine which arose over the past years. The third edition of The Sports Diving Medical by Dr Charles Paul Azzopardi and Dr John Parker gives a straightforward and accessible overview of the fitness to diving assessment process, the risks involved, followed by a detailed discussion of each body system, the relevant pathologies of every system and how diving affects each system and how to assess and mitigate the risks involved.