Is sliding on ice the same as sliding on water?

Similar but not the same. First rule: Don't panic, get skid under control. Second rule: Apply the first rule. Sliding on water is purely down to speed. The faster you go the less ability the tyres have to dispel the water. A cushion of water builds between the tyre and the road, traction is lost and aquaplaning (sliding) results. Don't brake, hold the wheel straight, take the foot off the gas and the car will come back under control very quickly. Sliding on ice can happen at any speed and black ice cannot be seen. Take the foot off the gas, reduce speed and do not brake, turn into the skid and gently accelerate until under control. Aim straight and (if no ABS) quickly pump the brakes until the vehicle stops. If ABS, aim straight and brake normally.