"Can I get to Oslob from Alona for whale sharking?" is a question I see alot on the forum, but I have yet to see a concrete answer to that question. Hope my story will provide some insight.
Walking around Panglao, you will see many ads and be approached by various locals, offering a trip to Oslob for whale sharking directly from Alona. The going price is 700-800 pesos per person, round trip. As they explained, there are two outrigger boats (which are slightly larger than the small ones) owned by the same person, and they do daily trips- depending on the weather; ie. no matter who you buy from on the island, you will be taken to the same boat.
It was a beautiful day and I opted to going to Oslob the next day, one way, with my luggage, and transferring to Cebu after. I was assured that this is a regular thing, my luggage will be dry and safe and tomorrow will be calm waters.
The next morning it was slightly raining but weather wasn't bad. Since the boat is too large to dock at alona, they take you by a "shuttle" to the main beach. From there you walk for probably 5-7 minutes through the water to reach the boat, ie. knee deep in sewage, seaweeds and some sea urchins.
After about 20 minutes on the water, a big storm started. The boat was thrown side to side, multiple wooden sticks holding the sails broke and tied back with rope, everyone were soaked head to toe with waves and wind hitting the passengers all trip long. The 2 hour trip took 4 hours and as we learned later, if something did G-d forbid happened, the boat has no radio to even communicate with the coast guard.
To top off this journey, upon arrival the boat could not dock near the shore and no small boats were provided. Instead passengers were instructed to jump off the boat, with your stuff (all but luggage) and swim to the shore. Then they had a small wooden boat to transport the luggage to the road. Obviously due to the storm, the whale sharks were cancelled, the return boat trip was not possible, and people were forced to get a hotel on Cebu Island instead. Since we only went one way (thankfully), we got off easy with taking our soaking wet luggage (which was placed under the deck upon boarding) and took the bus to Cebu.
My tip: beware! You are better of taking the boat to Argao at 4 pm the day before, hands down. If you are advantageous, make sure it is sunny with no sign of rain on sight before taking on this journey.