Two types of danger: the waves/undercurrent and people
For the waves: be very very careful, bathe at rising tide (so you'll be returned to the beach should you be taken by currents) and stay where you can touch the seafloor. There's no lifeguard and the locals don't swim...
People: during the day families and guys playing football, at night dubious people.
Your gear and attitude. Men won't have a problem (except if they don Speedos rather than roomy trunks) but ladies will attract attention. Women, if you insist on a bathing suit, I strongly recomment a pareo or sarong. You won't get abuse but you may get way more interest that you'd have bargained for. You can also bathe fully dressed!
Mauritanians are wary of the sea, they don't sail or swim.
In the airport the custom officers are spread everywhere. Whenever they see a tourist they tend to take money from them. When i reached the airport, i had to give money to as many as 10 officers and lost $2 at the airport alone.
Mauritania became independent in 1960, like all other French colonies.
Unlike other countries, Mauritania was not fully colonized because there was nothing there to justify real French occupation.
In 1960, the country became independent and since then all garbages of the city of Nouakchott have been thrown away from houses, then brought on a big field out the Nouakchott. Between the beach and the road to Nouadhibou, on more than 20 km, you can see the 45 years garbage abandonned by population. This generates bad smell but also a neverending threat of cholera.
Mauritanians are very dirty people. They don't use water and throw evertything away where they are. It is very common to see a big house of a billionair surrounded by its garbages.
Nouakchott like any other city in Mauritania has crazy drivers. normal driving rules are not taken straight. if you need to go somewhere just take a taxi and escape a possible car disaster like the one you can see on the photo.
pic taken in bg Avenue Abd El Nasser
Fishermn are found on the Nouakchott beaches where they keep the fishes for sale. They are fresh and cheap.