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rslifkin · 09-07-2020, 10:03

Absolutely correct. Even idling in forward, there's usually decent rudder response unless it's a boat with unusually small rudders. Just don't expect a powerboat to respond to rudder like a sailboat while coating along in neutral (unless it's a slow boat with a big rudder). You'll still have some rudder in neutral, but not a whole lot.

Cadence · 09-07-2020, 10:20

Quote:

Originally Posted by valhalla360

If you are coasting along in neutral, yeah, the small rudders are less effective.

If you are using them to direct prop wash, it's not really true. Most power boats, the rudders are directly behind the prop and roughly of similar size to the prop. Plus they simply put out a lot more wash with big engines driving large fixed props, so you have more to work with.

With a sailboat with a barn door size rudder and a tiny 2 blade prop, the wash really only hits against a small percentage of the rudder and there is a lot less wash, so overall, it's not a huge impact. If it's the old keel hung rudder with the half circle for the prop to fit in, you may get almost no wash redirection by the rudder.

By leading edge it's the area in front of the axis or shaft. A little more is going to help no matter what size prop. I see what you mean, A spade rudder is designed for sailing and that little prop probably has no effect.. I was referencing the power boat post about the v drive.

MicHughV · 09-07-2020, 10:26

I have found that on a sailboat, turning the rudder at low speed, even without engine propulsion, can turn the boat without much trouble, due to it's size....
a powerboat less so, in neutral, my experience with power boats is little helm response....or invariable...too little...too late...
a power boat with outboard(s) is TOTALLY dependent on the engines for turning...trying to turn an outboard without being in gear will provide absolutely zilch turning effort.

Shrew · 09-07-2020, 10:31

Quote:

Originally Posted by ol1970

I......my current 24 foot boat being a v drive it’s about as challenging as it gets because the rudder and prop are nearly in the middle of the boat.

Quote:

Originally Posted by Cadence

I'm familiar with v drives thus the question. Even your diagram contradicts the wheel and rudder being forward.

Hmmm. I read that and assumed he meant Center-line (as in a single).

The engine and drive would need to be very, very far forward to place the prop and rudder toward center (forward and aft) which I've never seen before.

valhalla360 · 09-07-2020, 10:42

Quote:

Originally Posted by Cadence

By leading edge it's the area in front of the axis or shaft. A little more is going to help no matter what size prop. I see what you mean, A spade rudder is designed for sailing and that little prop probably has no effect.. I was referencing the power boat post about the v drive.

Most inboard power boats use semi-balanced spade rudders, which means somewhere around 10-40% of the rudder sits in front of the axis of rotation. A lot of modern sailboats also use semi-balanced spade rudders.

They are smaller on power boats because that's all you need. With greater thrust, you don't have to rely as much on the rudders (hence the common suggestion to leave the helm centered and just work the gear shifts). With our power boat, if we were coasting forward at 2kt and I put both in reverse, forward progress was stopped within a second. With our 25hhp sail catamaran, even goosing the throttle, it could take 4-5 seconds before forward progress is stopped and while you are doing this, you are relying on the rudders for steering.

We had V-drives in our power boat...really doesn't impact handling compared to an inboard straight drive. What it does, is allow you to mount the engines further aft without introducing an extreme propshaft angle.

Cadence · 09-07-2020, 10:46

Quote:

Originally Posted by Shrew

Hmmm. I read that and assumed he meant Center-line (as in a single).

The engine and drive would need to be very, very far forward to place the prop and rudder toward center (forward and aft) which I've never seen before.

In retrospect that is probably what he meant. The v drive perplexed me. A straight drive or v drive is going to have the prop and rudder in the same place.
IMHO, the only place for an outdrive is on a trailered boat.

MicHughV · 09-07-2020, 10:50

If nobody is on the dock to catch your lines, I've made it a habit to arrange to have a line leading from the mid cleat on the boat, back to where I"m standing, as I pull into the slip, I will arrange to have this line looped, usually by throwing it over the first dock cleat, not tied, around the first cleat on the outside edge of the dock...I will feed this line out as the boat moves into the slip and when I'm where I want to be, I will cleat it off, leaving the engine in gear, with the helm turned so the butt of the boat will be pushed into the dock.

This will keep the boat snug in position along side the dock, giving me time to arrange my other docks lines. When done, kill the engine.

It takes a bit of practice, but once you get the hang of it, very easy.

introverted · 09-07-2020, 11:03

Most of the power boaters at my marina line their boats with rub rails and even attach them to their slips. The ones without bow thrusters just get their stern in to the slip and then jam it in. The ones with thrusters spend about 10 minutes trying to perfectly line up an entry in to the slip before jamming it in. Oddly, my neighbors seem to be the ones that have the least trouble, but I attest that to me being a good dockhand.

MicHughV · 09-07-2020, 11:48

powerboaters typically also tie into a slip, going backwards, thereby having the after deck available for getting on and off the boat...
some boats go backwards with relative ease.....others require a bribe...

Stu Jackson · 09-07-2020, 11:49

I look at a lot of powerboats when I travel and in my marina. Almost NONE of them in that 30 foot range have any way for the helmsman to get to the docklines once he actually gets into a slip or a side tie. The helms are inside, with only a sliding door to the cockpit.

The traditional trawlers at least have a door adjacent to the helm.

Some of the Ranger tugs have outside steering stations, too.

Without easy access to the outside, it seems to me to mean that a crew is a necessity.

MicHughV · 09-07-2020, 13:32

who wants a powerboat in the first place ???

mvweebles · 09-07-2020, 15:15

Quote:

Originally Posted by MicHughV

who wants a powerboat in the first place ???

I did the Baja Ha Ha - a 3 leg 800 nm rally - 15 years ago on a Willard 40, cruising speed 7-1/4 kts, one of four power boats in a fleet of 160, most of whom had 6.25+ cruising speeds under sail, just not always on the desired direction. We were routinely in top 10 arrivals. Over two days of good sleep, decent wine, and nice sunsets, we watched 150 boats arrive with many,/most crews looking like Bataan Death March survivors.

We burned about 175 gallons of our 700 gallon diesel capacity for the 800 nms and, unlike many sailboats, spent zero time scrounging for fuel or water along the desolate Baja coastline.

I'd guess that of the 156 sailboat fleet who still have boats, many have converted to power.

Suspect that answers the question.

Peter.