How soon after a ptosis correction (with incisions) can I go scuba diving?

This is far too early for such a stressful activity for the eyelids in my opinion. Please talk with your surgeon and be honest with them regarding what your are planning. Yes being too active too soon after surgery had the potential to negatively affect the result.

I would not recommend that you scuba dive that soon after surgery, and especially being away for that long(10 days).  When you dive you are increasing the pressure on your body and may have a mask squeeze. This pressure will effect the healing and can increase swelling and even can cause bleeding. This is an unnecessary risk. I would suggest to either reschedule the dive trip or the surgery! You must discuss this with your surgeon ASAP!

The best resource of information would be your board certified plastic surgeon as he/she knows your condition best. Each surgeon has a protocol to follow and the time for returning to activities also depend on the healing rate of an individual. Typically, patients are advised not to get in contact with potentially contaminating sources for the first few weeks to a month post op to prevent development of infection. 

This is great question for your surgeon. Even if they take extra efforts to close the wound and you are a fast healer, you risk being far away from expert care in the rare incidence you get into trouble.Sea water, boats, tropical environments are all hosts for unusual bacteria and organisms your broken skin may not have the ability to fight. All risk is relative so the perhaps your surgeon or your anatomy dictates otherwise.

All surgery is incisional, regardless of the modality.  It would be inadvisable for you to scuba dive shortly after the procedure for a multitude of reasons-pressure, the mask, and there could be an infection risk.  It is best to delay either the trip or the procedure.