New Zealand fishermen were relatively slow to adopt new technologies such as sonar, which used sound waves to record the water depth beneath vessels. This fish-finding device, demonstrated by a distributor of marine electronics in 1978, showed water depth, what the sea floor consisted of, and how fast the fish were moving. Many fishermen preferred to rely on their intimate knowledge of the coast rather than pay for expensive devices. As sonar devices became more affordable, they were readily adopted. However, as more and more technology entered the industry the capital outlay necessary to invest in fishing boats became too much for many small and part-time operators.