Driving a Single Screw Inboard

[The Dog House]

The F26 thread got me thinking about the challenges of driving a single screw inboard. I use spring lines and can handle pretty much any situation, but others have stated that they do not use spring lines. I'd like to get opinions on how to handle different situations and maybe learn something. How would you handle this situation when driving a single screw inboard?

Boat is docked portside to with boats in front and behind
4 knot current on the stern
10 mph wind on the dock

I leave the dock in this situation using a bow aft spring line. I run a line back to a cleat from the bow, loop the line around the horn of the cleat, and then run the line back to the bow. I have a crew person on the bow tending the line.
I turn the wheel into the dock and go forward at idle. This springs the stern out away from the dock without the boat moving forward or backward. When the boat is at an angle about 60 degrees from the dock, I have the crew person on the bow release the spring line and pull it in. As they are doing that, I back straight out until I am clear of the boats tied to the dock. At that point, I can go forward and turn the boat to wherever I want to go. It's a fairly simple maneuver but requires 2 people. What are some other ways of leaving the dock under these conditions?

[mikeandanne]

I have never had a single screw inboard just outdrives but have some experience with sail boats which may be easier to move around on by yourself and that manoeuvre you describe sounds good, if you pull the boat back first closer to the one off the stern it gives more room....have to say I would always try to dock a boat bow into a prevailing current though which would make escape a little easier.

The only thing different with the sailboat would have been extra fenders forward so you could plaster boat against dock then once stern out current would keep you out while you uncleat spring...thats it for me...Mike

[The Dog House]

....have to say I would always try to dock a boat bow into a prevailing current though which would make escape a little easier.

My homeport is in a tidal river, so while I always dock bow into the current, the current reverses direction every 6 1/4 hours so what was the current direction when I docked the boat is not necessarily what the current direction will be the next time I use the boat. If I use the boat two weeks in a row, the current will almost always be on my stern when I'm leaving the dock.

[mikeandanne]

Aha, now I see....I actually thought that was an example situation like a river, not tidal...sorry bout that...Mike

[K4282]

Like I said in the earlier post, I just steer mine, they won't go straight in reverse but with the wheel cut to the right, then sometimes hard left and forward to force the boat back where I want it. I sold it to a friend 2 years ago, my method may not be as pretty as yours I guess but I always did it myself and have never hit anything

[larryeddington]

By just touching it into gear and out you will find the boat will move just a few inches forward but stern will jump with rudder over as you suggest.

[captainmaniac]

Your approach sounds like the right one to me. Being right hand drive it will pull to port when you go into reverse, so if you were tied starboard side to with the same conditions (4knot current from behind, wind on the dock) you might be able to just put the wheel full to port, put it in reverse enough to 'hold' position, and let the prop walk pull you away.

Radical option B : add a bow thruster. I know it is a cheat, but I have started seeing them on 25' stern drives!

[The Dog House]

Radical option B : add a bow thruster. I know it is a cheat, but I have started seeing them on 25' stern drives!

I keep looking at stern thrusters. Would a stern thruster or bow thruster be more beneficial in a single screw inboard? A stern thruster would allow me to move the stern to starboard, something I can't do now.

My problem with any thruster system is the system would cost more than what I have invested in the boat. If I could get a system for $3k -$5K, it might be possible. Every system I've seen so far has been around $10k for my size boat. Maybe in time the prices will come down. We'll see.

[captainmaniac]

These guys are more of a 'bolt on'. I have seen on 25 footers up to a 43 Silverton...

https://sideshift.com/

[larryeddington]

you have stern thruster defacto with lots of side thrust from rudder in ahead with rudder and side thrust in reverse as well. Rudder is ineffective in reverse but the normal side thrust of the prop is always there. Read Chapmans seamanship to full understand that due to the prop setting at an angle to level causes a side thrust in reverse. In ahead the rudder will neutralize it.

[captainmaniac]

you have stern thruster defacto with lots of side thrust from rudder in ahead with rudder and side thrust in reverse as well. Rudder is ineffective in reverse but the normal side thrust of the prop is always there. Read Chapmans seamanship to full understand that due to the prop setting at an angle to level causes a side thrust in reverse. In ahead the rudder will neutralize it.

In a 4 knot current against a 10 knot wind, the degree of side thrust he will have from the single is not enough to fight those conditions. Don't want this to sound like a challenge or preachy or get in to a bun fight, but I helmed my father's 28' Sea Skiff (single engine) for over 20 years... The prop walk helps in certain conditions, but can also be easily over powered by wind or current. It won't walk you sideways very fast, it won't win a fight with a 10 knot side wind, and after being in reverse for long enough your backwards momentum will cause enough water flow over the rudder to make the rudder useful, undoing the benefits of the walk. If you have 4 knots current on your transom, that's enough for your rudder to work for you, whether the prop is turning or not.

If you really need to go sideways without moving forward or aft, your only options are spring lines or thrusters (or other boaters on their swim platforms or bow pulpits pushing you sideways). Or a different docking location.

[The Dog House]

you have stern thruster defacto with lots of side thrust from rudder in ahead with rudder and side thrust in reverse as well. Rudder is ineffective in reverse but the normal side thrust of the prop is always there. Read Chapmans seamanship to full understand that due to the prop setting at an angle to level causes a side thrust in reverse. In ahead the rudder will neutralize it.

I understand all about prop walk. There is no prop walk to starboard, however. Moving the stern to starboard requires a thruster or a spring line. Prop walk to port is also limited and must be performed intermittently. It can be done, but continuous thrust from a thruster is much stronger and can overcome stronger wind/current conditions. While prop walk can be useful at times, it is more often a hindrance than a help.

[JimK]

You have probably seen folks who have taken shots at making their own stern thrusters out of trolling motors. While most that are devised of a single trolling motor do not offer much help, I thought this one was interesting in that it combined two motors which I think would double or nearly double the thrust . http://www.all-about-houseboats.com/che ... sters.html

[The Dog House]

You have probably seen folks who have taken shots at making their own stern thrusters out of trolling motors. While most that are devised of a single trolling motor do not offer much help, I thought this one was interesting in that it combined two motors which I think would double or nearly double the thrust . http://www.all-about-houseboats.com/che ... sters.html

I like this idea. For the 40 foot houseboat he used two 55 lbs. thrust trolling motors. How much thrust do you think a Trojan F26 would require?

[JimK]

That's a good question. I looked at commercially available bow thrusters and they call for 55-75 lbf for a boat the size of an F26. However, I think they have added efficiencies like tunneling built in that improves their performance. I suspect that the dual 55 lbf trolling motor setup would move the F26 well.