Not sure where your looking to dock exactly, we are at Johnny resort. It just west of the rt 2 bridge on the portage. I have a 27ft regal with a b3 outdtive. I am able to launch and recover my boat there at johnnys. We have several 25 ft sportys that are single screws. They normally have no issues with water depth. In the late fall the water can get low in river. In fact I've seen it be basically dry b4. But most marina are dug deeper. If your looking to be down town you should not ever have a water issue. The normal depth after the train bridge west seems to be about 5 ft on most years. This year we had great water, several times I had to.put my Bimini down to get under the train bridge. And that is something else to consider, if you are planning to west of the train bridge and you can't fit under it, you are on their schedule. Normally just a phone call gets it up quickly, but if there are busy you wait an hr or so.