Normal?
If the PWC sits up for an extended period of time, then you may have the strong odor from fuel. When the PWC is in motion, the ventilation system should draft air through the inside hull and remove expolsive vapors.
When your not using the ski, it may be a good habit to make sure the gas is turned off. If your not seeing any fuel, then there is probably nothing to worry about. I'm assuming the ski runs well. If your carbs and fuel system is in bad shape, then you could be siphoning fuel into your carbs from the tank and into your crank causing a strong odor. But if everything runs good, the smell is probably normal.