Crewing on the African coast was a constant problem, the mortality rate was high, through accident and sickness. But this was, in the case of merchant vessels probably far less that the loss through desertion, for once clear of the port there was little chance of a man being arrested and brought back. Formalities, both when sailing from England and arrival in South Africa were mostly confined to the articles of agreement for the crew and passenger declaration. Immigration and emigration officials as we know them did not exist.
The lure then to desert on the South African coast were the gold and diamond fields, Captain Crutchley in his book says it was virtually impossible to prevent the men from deserting. It has to be said that this 'practice' was not always seen as a bad thing by masters of vessels laid up waiting for a cargo, it saved the ship having to pay the wages.
If you go to the Old Naval Cemetery in Simon's Town you will find many graves of Royal Navy Kroomen, the word Krooman must have been inherited from the Dutch, it was the normal rating given to a locally recruited non-European.
Very few were ever known by their proper names, very likely the officers never bothered to find out what a man's name was.