River-class mine hunter

The River-class mine hunter is a class of ships ordered in 1978 as research vessels to be operated by the South African Navy for the Department of Transport to circumvent the arms embargo in place at the time. They were originally named Navors (Afrikaans for "research") and numbered 1 to 4

The first ship Navors I was shipped to Durban from Germany in June 1980 for fitting out, shortly followed by the second. The last pair were built in Durban. The vessels were painted blue with white upperworks and formed the First Research Squadron. They were renamed in 1982 after South African rivers - (Umkomaas, Umhloti, Umgeni, Umzimkulu) but continued to fly the national flag and not the naval ensign. The prefix RV was only changed to SAS on 3 February 1988 when they were formally accepted as naval ships.