Answer:
Durban and East London are important for the growth and development of the Wild Coast SDI because they are two major coastal cities in the region.
Both cities have important ports, allowing for the import and export of goods and services to and from the Wild Coast SDI.
This provides economic opportunities for local businesses and encourages investment in the region. Both cities also have airports, which provide access to the region for both tourists and businesses.
They also have major infrastructure such as highways and railways that provide transportation and access to the rest of the country.
All these factors contribute to the growth and development of the Wild Coast SDI.