We were just on the Crystal River a month or so ago and loved it. Other than a 5 foot bar at low tide at the last set of markers before you pass Shell Island, the river and approach channel is plenty deep. We did a short video,
Tarpon Springs to Crystal River - YouTube . The best anchorages on the river are at Kings Bay. Even with your 4 foot draft, you will need to feel your way around to find depths for
anchoring. The area near the restaurants, etc. look like they would be great but there is lots of 3 foot depths there. There are a few wide spots in the river, but be careful since there are also lots of rocks in the river. Kings Bay gives you access to all of the Manatees. Chuck