Just to be clear, all Tesla Model 3 and Model Y for Europe will be coming from Shanghai in Q4. Berlin may start production of Model Y before the end of the quarter but the vast majority of Model Y will still come from Shanghai. Nothing will be coming from Fremont.
Tesla do not own any ships or have any dedicated ships, they generally charter complete ships to ship to Zeebrugge (Europe) and Southampton (UK & Ireland) primarily. Last quarter we saw Koper in Slovenia being used. This cut days off the shipping time to Zeebrugge but meant that lots of road transporters from all over Europe were required to move the thousands of cars from the port to customers all over Europe in time for the quarter end. Cars unloaded in Zeebrugge can be crossloaded on to other ships heading to Spain or Norway or even UK, trains to Denmark & Sweden and road transporters. Zeebrugge is the No 1 car importation centre for Europe and so has well established transport links for the movement of new cars. Some ships in Q3 carried on to Oslo to satisfy the huge demand from Norway. We also saw early in Q3 that Tesla unusually used scheduled services (expensive in comparison)to ship some cars manufactured in Q2 to Europe. Reasons for this are unclear - some suggest that the cars could not be shipped on time in Q3 because of the chip shortage whilst others suggest the ship scheduled to deliver the cars was unexpectedly delayed in dry dock and there wasn't time to reschedule another ship so close to the quarter end.
Not every ship that departs Shanghai for Europe will be carrying Teslas - a fact that some folk find difficult to grasp. Nowadays there are lots of Chinese manufactured cars eg MG, Volvo, Polestars etc that are exported to Europe. Car carriers don't just carry cars - they carry buses, trains, tanks, helicopters, agricultural equipment in fact anything that can be rolled on and rolled off. A lot of stuff in that list comes from China.
Port congestion has worsened over the last 18 months. Initially it was just containerships that were affected but now car carriers are feeling the affects at certain ports too - this has a knock-on effect to their schedules. 2 years ago you could almost set your watch to a car carrier - their schedules were published about a year in advance and ship captains did everything in their power to keep to schedule. Nowadays, the schedules seem to be revised almost daily and rarely go beyond 2 months ahead. Likewise with port schedules - some ports no longer publish their forecasts. Port bookings are 'TBC' and ports are being run on a first come, first served basis. Big shipping companies are sabre rattling with threats of 'taking their business elsewhere' but 'elsewhere' is in the same predicament.
You just need to see the number of ships anchored off Shanghai to get an idea of the scale of the problem. Admittedly, it always has been a popular location for ships 'awaiting orders' but the anchorages are overflowing. I have noted a reduction in the number of car carriers anchored off Shanghai this month and wonder whether the delays (currently down to about a week or so now) have made other other ports more attractive. We certainly saw Tesla use other docks in Q3 to ship cars to Europe.