Manado haritasında DAMRI KSPN Manado-Pantai Paal Minibüs hattı

This DAMRI bus originates from the airport, but on request (WA 082193084450, indonesian only) they will pick you up around terminal Paal Dua (old schedule shows a whole tour in Manado city). Depending on the passengers it will stop in Tangkoko and Pantai Paal.
Departure and return hours are a bit flexible, but as the bus returns to Manado a daytrip to the beaches is possible.