We stopped in Luderitz for few days. The clearance process was very simple with all the offices very close to the mooring. We only had to pay customs for after hour work (100 N$E).
There is no ship chandlery for yachts, there may be a hardware shop that has boat related items but I would not count on it.
The bay was very well protected but also very windy when we stayed there. You are allowed to anchor only in the harbour bay where the water was not clean enough to run the watermaker.
There is a Yacht Club, not more than a Pub near the anchorage. In theory you are allowed to use their showers between 9am and 12pm, however most of the time the water was cold and they were not really welcoming us. There is a wifi also working when they are closed in the morning. Not fast but we did not find anything better in Town. There is a Laundry not far from the Yacht Club.
There is a guy called Andrew living on a trimaran in the harbour that owns two buoys and we rent one from him. He was very helpful and friendly. He charges N$50 per day, or he tells you what he likes to drink.
You are apparently allowed to use the dock in front of the Yacht Club for the dinghy for free, however initially we were asked to pay for it. Andrew told us not to pay and he may have talked to them. After the first day nobody asked for anything.
There is no diesel available (if needed you have to buy it from the gas station in town and carry in tanks).
There is water available, you need to arrange with Port Control. The minimum quantity is 7,000 litres. We paid about N$ 450 for water and docking. They come with a large firehose fitting without an adapter for a small pipes. However they found a solution and we added a small tip to the the amount above.
There are two supermarkets (OK food and Spar) with all the essential food available, however we did not found good vegetables.
The coffee is not as good as in Cape Town. A Coffee place we liked is “The Garden Cafe” close to the Yacht Club, but the internet there was not very poor.