It's pretty hard to hide it from anything. Its surface is ~17000 m² (a tennis court is ~260 m²), and is 75 m high (~ 25 floors building - probably half of it under water, but still). And that's a mid-sized carrier according to Wikipedia.
It's not built for hiding at all, that's what submarines are for (and that's where our nukes are).
But the ocean is very very huge to find it still.
Well clearly since the De Gaulle is using a fitness app it's working on it.