With diving insurance it is not easy – information is worth it. Basically you will need one, one way or the other. In Egypt you pay about 7-10 Euro per day and you won’t dive without it.
Often students tell me that a pressure chamber trip and diving accidents with the personal health insurance, private or legal is irrelevant, would be covered. There may be insurances, which take over e.g. a complete e.g. pressure chamber therapy.
Usually this is not the case.
Of course you will not be charged for first aid because diving accidents are insured, but because you will not leave them on the shore. Accidents abroad are a science in themselves anyway. Inform yourself in good time. Treatments e.g. in a pressure chamber are very expensive.
That is why I can only recommend that you take a serious look at the subject of insurance.
Special diving insurances are available at Aqua Med or DAN and cost between 49.- and 100€ per year. Ridiculous in comparison to the actual costs that can arise.