*Looks at world map*
That presupposes secured and working canals. I don't think Panama and Suez are still a thing and, even if they are, they're likely easy for Nod to fuck with. That means any ship in one place will need to do the whole circumnavigation of the landmasses to reach their AOs. Nod would only need to station a few wolfpacks near the southern tips of South America and Africa to interdict any change of ocean or attrition forces in transit.
Both passages are at high latitudes and prone to stormy weather, and Earth's climate hasn't become gentler with the rise of tiberium. Sustaining a "wolfpack" implies either large ships, small ships, or submarines. Nod doesn't really do large ships, small ships can't operate sustainably around those areas for very long, and as for submarines, we don't have a lot of evidence for Nod attack submarines.
So, welcome back to the situation of the Age of Sails until Suez and Panama are back. South Africa (and Durban in particular) is in consequence a strategic location for all maritime transit. Strategically speaking, the best solution is likely to let Durban have the next shipyard to help secure high sea travel in the region without exposing assets in transit and then build a shipyard in Rosyth/Hampton Roads/Dakar to offer redundancy in case of an intensification of the sea war that would result in an interdiction of travel below South Africa, as a bare minimum.
No see.
The key point here is that the shipyards aren't tools for
securing inter-continental sea traffic, because the ships can and do go anywhere in much less time than it takes them to be built. Think of the situation during the World Wars. The areas in which the ships were fighting were
not the areas in which the ships were built. You don't want your ships fighting out of the same naval base in which they were built if you can help it, because it means the precious construction yards and the partially built ships inside are
far too close to the war zone.
If you're worried about Nod contesting control of, say, South Africa and the naval passage between the Atlantic and Indian Oceans, you don't respond to that by building big navy cruisers
IN Durban. You build them somewhere else and let them steam south to Durban in big squadrons once there are enough of them ready.
The last time I can think of that someone tried to defend their control of a port city with a warship constructed in that same port city was when the Confederates tried it with the
Merrimac, and that didn't work out too hot for them.
The rules are a little different for the hydrofoils, which are shorter-ranged and not really
great for long ocean voyages even though I'm sure they can manage. But our big ol' cruisers and the older capital ship classes? Almost certainly nuclear powered and more than big enough to do well on the trip. They're much less location-dependent.
