Knowing Egypt is something that we should do once in a lifetime. I would say several, but even once. Egypt is not to be missed. And if you are in Greece, you have part of the way. it's possible visit Egypt from Greece.
Travel between Greece and Egypt It is not complicated and with a little organization we can discover, in the same vacation, two of the most interesting historical and cultural destinations in the world.
There was a long time by boat between Crete and Egypt but these trips did not last long. There are some commercial lines that go from Athens to Cairo, but tourists do not usually join freight looking trips so you have to keep looking for options since at the moment the Greek ferry companies do not offer the trip to Egypt.
And one option is to use the companies of Cyprus ferry companies. And it is not necessary to travel to Cyprus as companies travel to the Greek Islands. What you should do is take a ferry in Piraeus to Rhodes, walk through Cyprus and from there get to Port Said, in Cairo. The ferry company is called Louis Cruises.