Tanganyika Blue Bay is about 1h15mn away from Bujumbura, which makes it an easy get-away at the week-end. The beach is nice and clean and you are given a mat on arrival. Do inquire about hippos or crocodiles, but usually staff are pretty good at monitoring the beach and keeping it out of bounds if there's any danger. The rooms are beautiful but way overpriced for the region (about 110-150 USD for a double). Worth calling beforehand and negotiating a rate before you get there.
Saying that, I have a big problem with the management. The manager is very friendly and will regularly come to greet you but is somehow lacking the imagination to improve his hotel. Service is a big let down. Sundays can get crowded and you may wait over 2 hours for your food (simple grilled fish) to arrive. Staff is poorly trained and is not given sufficient responsibility to make decisions in order to offer good service. Everything you ask for is "difficult".
Once we spent the night there, and while they usually can serve dinner on the pier (nice romantic touch), they refused to give us a table saying the manager had reserved the whole pier for his personal use. He only turned up 1h30 later, after we'd finished our dinner. Turns out he would have happily let us eat on the pier, but his staff was too scared to ask him.
Tanganyika Blue Bay has great potential but they should aim to do better. Until then it will remain a day get-away, but we won't be overnighting there anymore. It's just not worth the money they charge.