Diabetes mellitus (Recreational Diving Guidance)

A diver with diabetes mellitus may have a hypoglycaemic attack while in the water, which may be fatal to himself or to his diving partner. The hypoglycaemic attack may be brought on by poor control of the diabetic condition or by an increase in physiological stress due to exercise, cold, etc.

The UKDMC has decided that diabetics may be allowed to dive provided that they are able to pass the standard medical examination and in addition, satisfy the following criteria and those in the attached article “Diving with Diabetes”:

1. The diabetic has not experienced any hypoglycaemic attack within the last year.

2. The diabetic has not been hospitalised for any reason connected with diabetes in the last year.

3. The physician in charge of the diabetic at the diabetic clinic must consider the level of control to be satisfactory. This implies that the long-term control of the diabetic condition must be good. A guide to this may be obtained from the HbA1c (should be less than 70 mmol/mol). The physician must also be able to state that he/she considers the potential diabetic diver to be mentally and physically fit to undertake the sport of diving.

4. There must be no microalbuminuria present. Any degree of retinopathy beyond background retinopathy is not allowed. There must be no evidence of neuropathy (sensory, motor or automatic), nor of vascular or microvascular disease beyond the background retinopathy in the eye.

5. Body Mass Index (BMI) should ideally be below 29.9 but must not be more than 34.9. To calculate BMI go to BMI www.nhs.uk and put BMI in the search box at the top right of the page. Where the BMI is borderline the Medical Referee needs to consider a waist measurement in men of greater than 105cms and in women of greater than 90cms is a cause for concern and the should use their clinical judgment taking other factors into account.

6. The physician performing the medical examination should be satisfied that the diver has a good knowledge of the risks being undertaken when diving, which are due to the diver’s diabetic condition.

7. No would-be diver under the age of 18 with diabetes is allowed to dive in open water, and may only dive in the pool with close supervision. The reason for this is that during adolescence, insulin requirements may vary within short periods of time due to the glucose demands of the body. Such changes are difficult to take into account when diving and the risks of hypoglycaemia in the water are high. By the age of 18, most growth has occurred and the doses of insulin required are more stable.

8. Please note all diabetics require an annual medical undertaken by a UK Diving Medical Referee who reviews and signs the last page of Forms A and B as described below.


The potential diabetic diver should obtain forms A and B. Form A must be filled in by the diver on an annual basis. Form B should be filled in by the physician in charge of the diabetic diver and the Diving Medical Referee and this too, must be done annually. A copy of both forms should be made and returned to Dr C.J. Edge, The Stone Barn, Gravel Lane, Drayton, Abingdon, Oxon OX14 4HY.


Reviewed Jan 2021