Maritime traditions that extend along coastlines are more vulnerable to disruption and disappearance than areal trading networks. The paper describes two cases from Africa, the likely early movement of Bantu speakers down the coast of West Africa and the Swahili trading diaspora that reached southern Mozambique by at least the seventh century. Both of these have disappeared from the ethnographic and historical record but can be recovered through archaeology and linguistics. A parallel is made with the trade route that linked the coastal region of Peru and Ecuador with Western Mexico and may have been active from as early as 4,000 bp until the Spanish conquest. The hypothesis is that areal networks, such as those in island Southeast Asia and the Pacific, which are driven by colonisation and bidirectional exchange, are more likely to persist because they are more resilient due to the number of broken ‘links’ they can withstand. Linear expansions may be driven by a quest for trade and resources but are usually not necessary to survival.