Hey gregg,
A local dive club would be the place to start. At least one of us will be diving at some point during your trip, and we're a friendly bunch so feel free to join. One of our members live in Tulamben full time, and some have homes there. Some are in the dive industry and make daily trips there. Check out our website, the link is in my signature. We're a non-profit club so don't worry about being taken for a ride
Good luck with finding a buddy.