There are several sub-dialects including:
- Bikol Rinconada (Iriga-Buhi area),
- Bikol Albay (Albay Province)
- Bikol Sorsogon (Sorsogon)
- Bikol Catanduanes
- Bikol Partido (municipalities surrounding Lagonoy Gulf)
The common Bikol is Bikol Naga, and is generally understood by other Bikol speakers.
The Bisakol varieties, while spoken in Bicol, are not Bikol languages, but are instead Visayan languages spoken in Bikol.
The Bicol is also home to other languages. Tagalog, for example, is spoken in most of Camarines Norte and in the town of Del Gallego, Camarines Sur. Hiligaynon is spoken in the southwestern Masbate towns of Balud and Mandaon while Cebuano is spoken in the southeastern Masbate towns of Placer, Cataingan, Pio V. Corpuz, and Esperanza.
Source: Wikipedia
In the 70's and 80's, our little town in Minalabac, Camarines Sur are learning Tagalog in their public schools. That's why my friends who went on vacation with us, find it easy to communicate with the Bikolanos using Tagalog.