You won't find anything high quality for under $500.
Waterproof/shockproof cameras come in two varieties.
1. A camera which is built from the ground up as a water-resistant & shcok-proof device
2. A camera which is built normally, but has an waterproof enclosure available as an accessory.
Cameras in group 1 are usually mediocre in terms of image quality or performance. Not horrible, but not top of the line either.
Cameras in group 2 will cost you more than $500. The enclosures themselves are usually $100+, which takes a chunk out of your budget.
Your best option at your price range is to get one of those tiny helmet/adventure cams (like the GoPro), or a digital still camera that has water resistance (like the Olympus tough cameras).
Or look for something used. Quality cameras are expensive