Torokina in Bougainville

I'm going to be traveling to Bougainville in mid March to mid April and an interested in getting to Torokina (west coast) - it's for research purposes more than tourism. Does anyone know what the transit situation is? I know it's boats only, but do you know whether most of the boats are from Buka or from south coast (like Kangu), or both, and what days they run? Any other info on Torokina would also be much appreciated.

Also, for the Bougainville to Solomons run, do you know if the boats from Kandu to Shortlands run only on market days (Saturday) or also during the week?

Thanks!!!