Family w/12 and 9 yr old boys - where to stay as base in the Riviera?

Nice is a big city. The Old Port area qualifies as "quaint" if you can ignore all the other tourists. I'd say there are two major reasons for staying in Nice: its status as a hub for public transportation (trains and buses) and its museums, particularly art museums. Do those advantages align with your plans? They were extremely important to me. Whether the city is walkable depends on what you want to see while you're there and where you are staying. I think Rick's guide book discourages staying in the Old Port area itself, probably because the infrastructure in those old buildings makes reliable air-conditioning and plumbing a bit iffy.

I went to Antibes on a day-trip and really liked it. It is atmospheric and didn't feel quite as tourist-overrun as some of the other coastal towns. However, that was in May.

Reality check: A lot of the Riviera beaches are rocky. The sandy ones may be packed towel-to-towel (or chair-to-chair) with sun-worshippers in July. The beach experience may not be at all as you imagine.

The quaintest places will be the small towns you haven't heard of, probably up in the hills rather than along the coast. One example is Biot; another is Vence (not too far from the incredibly touristy St.-Paul-de-Vence), and neither of those is undiscovered. Those hill towns are not convenient places to stay without a car when you want to travel around the area. Even with a car, you'd be dealing with extra travel time to get anywhere. The fastest/simplest way to see a good bit of the Riviera is to stick to the coastal towns and use the train, even though it means dodging other tourists. Traffic on the coastal road was sometimes severely (and unpredictably) clogged during my early-May visit, so I wouldn't want to drive; others may have a different point of view.

Be sure to check on parking arrangements while you search for lodgings.

Seconding the rocks. Sandy beach are few and far between in the Riviera. Bring some kind of water shoes (or buy some there).

I recall seeing somewhere having a snorkeling guide place - maybe in St. Tropez or thereabouts. We were on the French Riviera with similar aged kids last summer and considered that. Places around Monaco are going to be packed. Nice is a city. (We ended in Cassis, and hiking to the Calanques, but that isn't near Monaco and doesnt sound like your cup of tea)

There are fine sandy beaches in Antibes (outside the main town) and around the Cap in Juan-Les-Pins. Antibes and JLP do indeed fill up in the summertime, and JLP is a holiday beach resort (note many of these fine beaches are private, although next summer some of these franchises are changing in JLP to an unknown degree. Antibes has more public space). Villefranche has a smaller beach that is large grain sand, but gets very full (there is a tiny private sandy beach on Cap Ferrat as well). Cannes has imported sand and gets very packed, all along it's length. I'm not a fan of the beaches there -- like being packed into a sardine can in the narrow strip of sand and you are paying top Euro for the privilege. If it is a single day, you can reach these beaches by car or by train.

St. Tropez is lovely and has sandy but a car is generally required as public transit links are confined to the bus and ferry.

In Nice, staying in the Old Town (Vieille Ville), Carre d'Or or the few blocks around Place Massena keeps you in proximity to the beach, transport and central attractions. The Port is also an area that interests some people as well, although it is further away. It's a city, with more to do and better transport links, but the center is very compact and transport very good (but parking is more expensive). East of Antibes to Nice and further east are pebble beaches (including Beaulieu, Eze-sur-Mer and Menton)

If your sons lead with French, they will get spoken to in French and get plenty of practice.

In many of the places along the shore, a car is not a necessity and in some cases a liability. Mid July is peak season, and the roads in and around many towns will be challenging. In fact, in places like Villefrance the car traffic is sometimes blocked into town. In peak season, a better bet is to rent a car for a few days and use it to travel into the hills, where access is tougher by public transport.

Antibes, in September, was my favorite. I'm not sure how the summer crowds would change the dynamic. Antibes had nice sand beaches (but there will probably be lots of jellyfish in the summer), a marina, walled old area, great old center with cafes and restaurants as well as one of the best art museums in the area.

When Gooster says large grain sand what they mean is sharp and pointy large grain sand. Water shoes or ouchy feet.

The traffic in season has to be seen to be believed. Fold in your mirrors and hope that the vehicle coming the other way has folded theirs in too.