Snorkelling does not require a Medical Questionnaire or a Dive Medical in Australia, but it can be a strenuous physical activity that may increase the health and safety risks for persons suffering from any medical condition that may be made worse by physical exertion (such as heart disease, asthma and lung disease), any medical condition that can result in loss of consciousness (such as epilepsy or diabetes), or having a low level of personal fitness due to age or physical condition.
Some medical conditions, such as asthma and respiratory disease, may also be aggravated simply through exposure to cold water or salt water mist.
Some people may also panic and get into get into difficulty while snorkeling, especially if they are not experienced, and this panic-related strenuous activity can aggravate some medical conditions such as heart disease (resulting in cardiac arrest and death), and epilepsy (leading to unconsciousness and drowning).
You may be required to sign a disclaimer by the dive operator if you elect to snorkel with a known and/or contra-indicated medical condition, or are taking medication.
Persons with a low level of personal fitness should seek the advice of the dive operator with regard to the environmental conditions at the snorkelling location particularly with regard to water temperature, currents, visibility, and safety procedures that are in place..