Several lines make the trip between Dumaguete and Dipolog in Mindanao.
Montenegro, Aleson or Cokaliong lines will have a boat departing every few hours from the pier in Dumaguete
The regular fare is 246 pesos on Montenegro or Cokaliong. If they are full you have to book tourist class which is 386 pesos. Some Aleson routes continue onwards to Zamboanga and Sandakan.
If you have an early morning departure it is a good idea to have money broken down ahead of time.
The ticket offices start with no change in the till and will just write on the back of your ticket what they owe you in change. It is very difficult to chase down the purser to get your refund.
In calm weather it only takes about 4 hours but during a storm it can take 5 1/2 to 6 hours. You ticket will have a bunk number on it and you can catch a few hours of sleep.
I prefer the Montenegro lines because the boat is smaller and it has good cross ventilation. On the Coklaliong you can be uncomfortably cool in the air conditioned tourist class cabin. If you arrive at the terminal just before departure the economy might be full and you will have to upgrade to the more expensive "tourist class".
I really don't care for air conditioning because none of the ones in the Philippines have thermostats to shut them down when it is cold. They just keep going and going and you can sick from the cold.
Blankets are issued in tourist class if you ask for them.
There are some great cafes as you leave the docks in Dipolog. An outstanding meal of shrimp costs only 50 pesos so it is a good idea to get refreshed before heading out on the trail especially if you are taking the bus down to Zamboanga.
Getting to town or the bus terminal takes a bit of haggling with the tricycle drivers. The standard fare is 40 pesos but that is per person and they try to get 6 people on the motorcycle side car.
If you don't have other passengers to split the fare with it will run 240 pesos.
That is far too much so try to hook up with other people as you leave the boat if you are traveling alone. Everyone is going to town because there is nothing at the pier except for a few restaurants and ticket offices.
Another option is to take a motorcycle to the crossing and take a 10 peso multicab to town but if it is your first trip there it will be somewhat confusing to figure it out.
I have stayed in Dapitan before but not in Dipilog.
Dipolog seems a clean and pleasant town with rather light traffic and the road heading south is very peaceful and beautiful.
Mindanao gets a lot of bad press but it is an amazing place to visit. Palawan and Mindanao are tops in my book but Mindanao doesn't have the tourist infrastructure that Palawan has.