Hi ,
Thank you for asking me the question.
＞I want to go diving in オオビキ島.
It's depending the wether condition include wave and wind.
> I am free on 20th, 21st Sep.
- If you have exactly only 2 days, you may have to choose : half PADI course (12m)
- If you can study Text & DVD : PADI course (18m)