Diving in Bira
Diving Bira is possible between April - October. Due to possible bad visibility, most scenes are closed from November - March. The Dive sites are varied, nice, and warm, and can be somewhat challenging due to the current which I personally love. The temperature varies between 26 and 29 degrees and visibility is mostly very good.
The peak season between July and August can be busy and because it's relatively low on tourists I would recommend booking in advance.
The dive sites are mostly wall dives, reef dives, and a wreck here and there. The village is situated along the coast and so are most of the hotels which makes this an excellent Divingscene.
Bira is a lovely small town all the way in southeast Celebes. Hotels. restaurants and cafés are all on the beach front which makes this an excellent place to go for a sunset walk along the beach while picking out your favorite restaurant or bar to have a meal and/or drink.
In the morning you can relax with breakfast while watching the sunrise and get ready to go diving. All the major sites are reasonable close by and between dives you will usually head back to shore.
How to get there?
Getting to Bira can be quite the trip although if you're doing a Celebes trip this is perfectly doable. Fly to Makassar, the main point of entry and then you can get a taxi or personal driver to take you to Bira in roughly 3 hours. The island is pretty basic outside of Makassar and I arranged for myself a personal driver and guide for 10 days to cruise around the island for less than 500$. This was with accommodation included.
To get to Makassar you can fly from Jakarta or Soerabaja if you happened to be on the mainland of Java. Flight from Bali is also possible.