Oslob, Cebu is approximately 3 hours ride from Cebu City and many tour companies offer packages that comes with canyoneering with the nearby Badian. The boats will stay just a few dozen meters away from the shore (if you are a strong experience swimmer, I think you can even swim back to the beach) where you will be given a chance to see the gentle giants or what locals call 'butanding'. Life vests are required while the boat is on the move but the boat man ('bankero') allowed some to remove them if they know how to swim. You will be given a 5-10 minute briefing on a nearby post by English-speaking locals and 30 minutes for the main event. Most 'bankeros' we spoke to knows how to use a GoPro and some with push you underwater (if you know how to swim of course) to take a great shot of you.
Another boat will continue luring the whale sharks by throwing shrimps (and they smell terrible, believe me) and you can see them opening their mouths to catch them. Their babies are like less than a foot long and they are really white. Above, you will see that they only have a small head (like almost a meter long) but when you see them underwater, woah! These creatures are huge but they are extremely harmless and cute!
Just be reminded that you are to stay 5 meters away from them at all times and touching them is prohibited and may cost you a Php 5,000 fine (US$ 103.41 as of today).