My name is XXXXX XXXXX I will be helping you today. Most questions will involve troubleshooting, and usually take many posts back and forth. Post back with questions as needed.
The problem you have here is that it is a bigger boat and you only have 1 single prop engine. All single screw(prop) larger boats are hard to handle at low speeds because the sterndrive is the rudder, and it the rudder has very little input to affect the boats steering at low speed. It is not a problem or a design defect of the drive. It is the design of the boat.
I'm in SW Florida where everything is canals down here is well before you get out to the open Gulf. I have 2 boats, an 18 foot with a single outboard. That isn't a problem to handle because it is so small. But I also have a 38 with twin inboards and a bow thruster. Thats not to bad becuase I have twin counter rotating props, along with the bow thruster. I can pull it in parallel to a dock, and walk it in sideways with the twin screws and the bow thruster.
At the same time, as a mechanic I frequently take boats out for test drives. The worst are single screw inboards (not sterndrive). They wander so much all over the place that those boats can be impossible to get out of the canals on a windy day. If the boat gets blown to the side it is pretty much impossle to correct. All you can do is a hard reverse, pull it backwards. And then try again forwards.
The problem is the design of the boats. All larger single screw wether it is inboard or sterndrives handle terriblely in tight quarters. Those boats are really not designed to be operated in tight canals unless you are very very good. Even then, when you get off course all you can do is a hard reverse and then go back into forward to try to line things up again.
Now for you there are only a couple fo things that will help.
1. Lots and lots of practice, and that is free except for the fuel you burn.
2. Changing the Bravo 2 drive for a Bravo 3 drive. The bravo 3 has twin counter rotating propellers and has much much better low end thrust than the bravo 2 does. And that will give you much better low speed steering.
3. Adding a bowthruster, that will help as well. At low speed if the bow steers in the wrong direction you can use the thruster to push it in the opposite direction.
That is really it. It is the design of the boat being so large and only having a single prop that makes it hard to steer.
Feel free to post back with questions