Official list of federal waters?

I do have our boat registered, licensed, and have bought tabs in the past, but it is just a small 10 foot boat with a 4hp gas motor.  I don't think I need to buy tabs every year for both the trailer and boat...just the trailer.

Does anyone know where an official list of federal waters in Washington state is?

...Registering your Vessel
Register your boat with the Washington State Department of Licensing. To navigate, operate, employ, or moor your vessel in Washington, you must have a Washington title, registration card, and registration decals, except:

• If your vessel is a canoe, kayak, or a vessel not propelled by a motor or sail.
• If your vessel is less than 16 feet in length and has a motor of 10 horsepower or less and is used on non-federal waters only.
• If your vessel is properly registered by a resident of another state or country who uses Washington waters for 60 days or fewer.

The registration card (the cutout portion of the Vessel Registration Certificate) must be onboard whenever you use your vessel...

- http://boat.wa.gov/regulations.asp