Shipping to the Channel Islands can be a massive headache because of the ferry schedules and local port restrictions. If you try to use standard domestic couriers, they will either refuse the load or hit you with insane "remote area" surcharges. For our projects, we always use a freight forwarder that runs dedicated commercial freight to Guernsey. They understand the daily ferry timetables from Portsmouth and Poole, and they have the right vehicle sizes to navigate the tight, narrow roads around St Peter Port. Going with a specialist is much cheaper than booking a general carrier who has to subcontract the sea leg anyway.