Harbour Low Speed Control Problem

[fish brain]

1. Put the kicker in the water, not running, with the tie bar attached. It acts like an additional rudder. You could have it in the water just until you get out of that narrow channel that you seem to be having trouble with and then pull it up.

2. Install a hydrofoil on the main. They help immensely with low speed control and tracking.

3. Try a four blade prop on the main. Combined with the hydrofoil, this combo works very well with low speed control and tracking among other improvements.

Exactly . My boat "wallows" at low speed. The having the kicker down will make a huge difference.

 

[BC Coast Pilot]

Steerage in your case is only applied with thrust, and in your case thrust aft of the rudder as its an outboard I dig my outboards in and trim down approaching the berth, leaving them up will push the bow up and indeed more bow out of water is more sail. The suggestion to TRIM DOWN is the best one I see, and speed is your friend. We often see what you're describing on larger ships with a large sail area. As we approach the berth and slow down the effect increases. Mitigate this by aiming high and allow for the set, even giving the odd "bump" with full helm before engaging ahead or astern (more effective trimmed down also) opposite rudder slowing the ahead speed and drifting transversely.....bodily.
Hope that makes sense, it does not make sense to me to add additional rudder etc, and we're not going to add a bow thruster .
There's a lot more to this including how the pivot point moves around, (to the bow with speed) and as you slow it moves aft. Just shifting weight forward would help too but the dynamics of the pivot point being at the bow when moving (that being 3 knots?) and moves to the stern when stopped are fundamentally what you're fighting. Ultimately they all back to the wind.
Hope this helps

 

[pcaker]

Steerage in your case is only applied with thrust, and in your case thrust aft of the rudder as its an outboard I dig my outboards in and trim down approaching the berth, leaving them up will push the bow up and indeed more bow out of water is more sail. The suggestion to TRIM DOWN is the best one I see, and speed is your friend. We often see what you're describing on larger ships with a large sail area. As we approach the berth and slow down the effect increases. Mitigate this by aiming high and allow for the set, even giving the odd "bump" with full helm before engaging ahead or astern (more effective trimmed down also) opposite rudder slowing the ahead speed and drifting transversely.....bodily.
Hope that makes sense, it does not make sense to me to add additional rudder etc, and we're not going to add a bow thruster .
There's a lot more to this including how the pivot point moves around, (to the bow with speed) and as you slow it moves aft. Just shifting weight forward would help too but the dynamics of the pivot point being at the bow when moving (that being 3 knots?) and moves to the stern when stopped are fundamentally what you're fighting. Ultimately they all back to the wind.
Hope this helps

Thanks for your response. I have not reacted much to this suggestion earlier, mainly because I don't think that I have much trim down movement available. Also, at very low speeds, and very low prop thrust, I am dubious that bow would be significantly depressed. I quite understand the theory however. Thanks.

 

[BC Coast Pilot]

Thanks for your response. I have not reacted much to this suggestion earlier, mainly because I don't think that I have much trim down movement available. Also, at very low speeds, and very low prop thrust, I am dubious that bow would be significantly depressed. I quite understand the theory however. Thanks.

The bow "riding up" with thrust is just a consequence, what we are really looking for is that deeper more perpendicular rudder effect.

 

[Macdeep]

Thanks for responding. I very rarely troll with the kicker, so I can't say. When I do maintenance test runs with the kicker, there are no obvious cross wind issues, but then I am moving faster than 3 knots. I have been boating for 50 years, so I am fairly experienced - not that I could not still learn plenty ! The primary factor in my opinion, is that the lateral area of front half of boat is too large in relation to its too shallow embedment in the water. In a cross wind, the boat pivots about the stern, as opposed to the whole drifting sideways. I also considered adding a vertical keel plate near bow, but too many negatives. At this point, I intend to try adding a rudder to the kicker.

Ya, interesting problem you got there. Sounds like you have it figured, at least the problem part... But I guess if the boat pivots around the stern, adding more rudder at the back probably won't stop it from pivoting any more than it already does. Might be time for a bow mounted electric motor or something?

I have a glass boat that's decently heavy for what it is, so I don't get an extreme bow swing, but it does catch a cross wind at times. The only thing that works for me in a cross wind is two fold - first, go a little faster than usual (which isnt ideal and at times not the best idea), and second is I just have to angle into the wind and dog track it a bit to combat the sideways drift etc, again, not ideal, but better than not docking. Hitting the trailer can be interesting, but it is what it is I guess.

Good luck!