Hi Mateusz,
Seaswift is the main supplier of cargo and freezer/chiller supplies (mostly food supplies). They usually move supplies around all of the Torres Strait Islands at a set schedule – which is available on their website (Saibai is part of top western cluster).
If you look at the interactives -> Jetty/Boat ramp section, There is a photo of what the vessel looks like, you can make assumptions based on that.
For the marine dock infra, TSIRC owns the barge ramp and SeaSwift pays them a certain fee (which might be available online, if you have a brief search). Hope that helps.
Cheers,
Sai
Sai Rupa Dev