Rand Water has boats which they use for sampling Vaal dam and the Vaal Barrage Reservoir. One engine of the main boat (Seacat 520) developed an issue with the gearbox where it was not engaging reverse.The boat engine is a Mercury 60hp 4 stroke engine model number 1F60453LZ, serial number 1C482811Upon assessment it was seen that the following needs to be done on the gearbox:1. replace bearings in the gearbox2. replace all seals3. replace water pump components.