
Is it necessary to be at least 18 to learn to dive. Your individual circumstances will determine the answer. You can take your junior certification course with children and then go deeper. Teenagers and adults can also pursue adult scuba certification courses. For both courses, you must be at least 15 years old and have at least a little bit of experience. Below are the physical and medical requirements required for each certification level.
Minimum age to scuba dive
The recreational scuba diving council (RSTC), recommends that children under 15 years old not scuba dive. Children as young as 8 years old can learn to scuba dive, and receive training. Because there is limited scientific study on the effects of scuba diving on children, this age requirement is not absolute and can vary from person to person. A qualified instructor should instruct children.
You don't have to be at least 18 to learn to dive. PADI and some schools may train children as young at ten. Children under 10 years old are considered junior divers. They will then be promoted to the appropriate adult level once they reach the right age. The British Sub-Aqua Club also allows young people to be trained. However, they must be 12 years or older before they can take part in any training programs.

You will need to meet your medical and physical needs
Divers with certain conditions may have difficulty safely diving. Divers with chronic or severe conditions, such as diabetes or medication, may have difficulty diving safely. Diving requires regular physical activity. Pregnant women should not attempt scuba diving. Before taking the plunge, it is a good idea to consult your physician if you have any conditions. More information about medical and physical requirements for diving can be found here.
To begin, you will need to complete a medical questionnaire provided by the Recreational Scuba Training Council, an organization in North America. This form can be downloaded from many places. The RSTC will assess the completed questionnaire and determine if the prospective diver must undergo a medical exam. Those who answer "yes" to the medical questions do not necessarily disqualify themselves from diving, but they do indicate that they may have a pre-existing medical condition that would interfere with their safety while scuba diving.
Courses available
You must be at least 8 years old to dive. The age required to dive depends on where you live. The PADI Bubblemaker program is designed for children if you are unsure if you are old enough. It teaches them how to dive, including pressure and buoyancy. They also practice in a pool. During this training they can dive to as much as 12 feet.
At least eight years of age is required to become a fully certified diver. While most agencies offer courses to children as young as 8, they won't give you the certification to dive in open-water. PADI offers Seal Team, the Bubblemaker program, and Seal Team for younger divers. Although this program may not seem like the best choice for beginners, it can be a great way to get a taste of the experience.

Certification requirements
Scuba diving certifications never expire, but if you want to teach scuba to beginners or start a business, you will need to have an instructor's card. Reputable dive centers will ask you about your certification, dive history, and number of dives. A refresher course may be necessary if you haven’t dived in six or more months. You can still keep your certificate valid, but it won't expire. However, you should make sure you are up-to-date on the most recent rules and regulations.
Five types of diving knowledge is required in order to attain scuba certification. The first two components are the classroom and the second an open-water dive. Each dive will be a simulation of an emergency situation, wherein you'll need to be able to return to the surface quickly. This section of the course works in the same way as obtaining your driver's license. To pass the open-water dive, you will need to complete a knowledge test and take an exam.