Bunaken currents - are highly variable. You should expect current on Bunaken, that said, on our visit last year we had virtually none. Much depends on the moon etc. This also has effects on what you see - but that is true of most destinations. The currents take you along the wall and it is an exhilerating tour of the magnificent fans, crinoids, reef fish, bigger things like black-tips, all sorts of jacks, turtles and Napoleon wrasse etc etc.
The point which seems to be overlooked here is that there is superb critter diving on the Manado side, which is also warmer than Lembeh and not subject to the currents that Bunaken sees. So staying on the Manado side gives Bunaken's walls and drift dives as well as critter diving on the Manado side. It is perfectly feasible to drive over to Lembeh and spend some time there. Lembeh is undoubtedly the best muck-diving. Another advantage of Manado is the oportunity for non-diving activites such as climbing volcanoes, visiting Tangkoko National Park for land-based critters like tarsiers, taking a tour of the highland areas and seeing the market in Tomohon. Manado itself is a typical noisy, dusty Indonesian town but if you are in Indonesia you might want to see what that is like - and it is easy to walk around, you will not get hassled on the streets.
