Manatees swim very slowly - about 5 km/h, which is roughly walking pace. They use their wide, flat tails to push themselves along, and use their flipper-like front legs to steer. Despite being so big, they are completely harmless and only eat plants - water grass, mangrove leaves, and floating weeds.
Old sailors used to think manatees were mermaids. When they saw one rising out of the water with a baby in its flippers, they imagined they had spotted a sea person. They were a long way off and probably very tired. Manatees are definitely not mermaids - but they do hug their babies.
Mother manatees are amazing parents. A baby manatee stays with its mum for almost two years, learning where to find food, where the best hiding places are, and which routes to take. They communicate by little squeaks and whistles, especially the mother and her calf.
West African manatees are now quite rare. People who care about them protect parts of the rivers where they live, and ask boats to slow down when they pass through. School children in Senegal sometimes go on river trips just for the chance of seeing one come up to breathe.