Unless the info post for a specific port mentions that character abilities will be affected in some way (which does happen sometimes), characters are subject to the same restrictions or lack thereof while in port as they are on the Barge! So if a character has access to summoning powers while onboard the Barge, they'll generally be able to use them during ports, but if their ability onboard the Barge is restricted or nullified (ex. due to inmatehood), those restrictions will remain in place during ports.