Trim. Speed, and Turning

[Zackman]

I am new to boat ownership this season when I purchased a used 22 Cuddy with the Mercruiser 350 Mag and Bravo 3 drive. The top speed of the boat is in the 56 to 58 mph range, but I almost always cruise in the 30 to 35 mph range. I have never had any problems getting on plane or adjusting trim (outdrive only, the boat doesn't have trim tabs) to optimize speed vs engine rpm.

Yesterday we were out for the first time in cooler weather and I found myself cruising at the lowest comfortable speed which is about 24 to 25 mph. This was fine until a began making relatively sharp turns. The boat steering seemed to be heavy and did not respond well into the turns. I found myself have to turn the boat relatively hard and the boat began to list. If I remember correctly it would list in the direction I was turning (i.e. turning left the stern would list to the left).

Instead of changing the trim, because I was not sure if I was trimmed high or low, I just slowed down and actually came off plane.

My question (sorry about the long description) is given the type of listing I was experiencing should I trim down more and increase throttle slightly or am I trimmed down too much already.

Typically once I have reached the desired speed I trim up until the boat starts to porpoise and then trim down slightly.

 

[QC]

Re: Trim. Speed, and Turning

First, what you desribe seems very normal to me . . .

With that said, trimming down is usually the best approach to hard turns.

Finally, I don't know of any v-hulls that don't list while turning. Tunnels stay flat, but that can be very uncomfortable for passenegers because it feels like they may be thrown out. I can also make a v-hull turn flatter with trim tabs applied opposite of the expected list, but it is pretty hard to do with your hands on the wheel and without blowing the trim tab breaker . . .

 

[stevieray]

Re: Trim. Speed, and Turning

BSman - welcome aboard iboats. I agree with QC's comments as they apply to a normally-powered single prop drive. Yours seems to be pretty powerful for a 22 ft and has the dual counter-rotating prop Bravo 3 to boot. Try trimming full down in the turns first at various speeds & see if that makes a difference.

 

[steelespike]

Re: Trim. Speed, and Turning

Not an expert but my guess is you were trimmed out too far for the speed.It is normal for a boat to lean inward when turning. The amount will depend on the trim,speed , boat design and weight distribution.Play with the trim at various speeds to get a feel for the best position for the conditions.As you slow; the bow will tend to rise trimming in will help this some and may help to stay on plane at a lower speed.But bow rise is of course a natural trait.

 

[Zackman]

Re: Trim. Speed, and Turning

Thanks for the quick responses, but I don't think what I'm experiencing is normal. I am probably not explaining it well enough, so let me try again.

At very low planning speed, at least what I think is low for this particular boat (The hull is rated for 425 Hp), the following occurs when taking a relatively sharp turn.

I begin to turn the wheel and get very little response as compared to what I'm used to at higher planning speeds. I keep turning the wheel slowly getting very little response until the boat lists hard to one side. The listing feels like a 500 pound man just jumped from the middle of the boat to one side at the stern.

The only action I can compare it to is if I have the trim too low at planning speeds I get a slight list to the left, but rasing the trim takes care of the problem. The listing I get at low planning speeds while making a relatively sharp turn is much more severe.

Did I just answer my own question?

 

[QC]

Re: Trim. Speed, and Turning

BSMan,

First, I don't think I would connect high horsepower capability with planing speeds. Not realy related. My boat can be bought with over 500 bhp and with my trim tabs up (out of the way) I can keep her on plane down to 19 MPH, trim all of the way in. I have a Bravo 1 and your Bravo 3 should be even better although I think your boat may be heavier. Mine is in my avatar . . .

I think I know what you are feeling though. In all three of my boats, there is a place when turning at slower speeds that she sort of pops up and feels like she's going over. Works both ways, but especially to port as I have only had single prop drives . . . Anyway, I believe it doesn't happen at higher speeds because the hulls tend to slide more, while at lower speeds she stays hooked up. Also, at lower speeds the helm does have less impact simply because there is less force from the water hitting the big rudder that your drive is, that might explain the slower response at slower speeds, trim being somewhat out would make her sluggish too.

Another factor is the drive is progressive heeling over at the same time pushing both laterally and now also up at the stern forcing the side further over. Maybe that's what you're feeling? A little positive trim (up) would accentuate that I believe. When I start to head into a turn, I pull my trim all of the way in and then start cranking the wheel. Somewhat simultaneously.

 

[Zackman]

Re: Trim. Speed, and Turning

QC,

The only reason I mention drive type and horsepower is that I thought there was always a compromise during the design process, but this was just an assumption on my part.

I hope to be out again this weekend, and I plan on trying the trim down through the curves at low speeds. I will probably go through the same turns a few times to try different trim angles, if its not too crowded.

Again, thanks to you and others for responding to my post.

 

[Bill Adkins]

Re: Trim. Speed, and Turning

Sorry, I am confused. Does your boat have a IO or is it equiped with a shaft drive and rudder system?

 

[Zackman]

Re: Trim. Speed, and Turning

I/O Bravo 3

 

[Bill Adkins]

Re: Trim. Speed, and Turning

So how does it all work in a turn if the tabs are both completely raised. I had a Sun Dancer for years with twin engines and it always laid on its side in a good turn. Have to be honest it never turned turtle and it actually was sort of fun. It had a lot of dead rise in the hull so it did well in the ocean, I used the tabs to make if more user friendly to the wheel in that with the tabs up if you made even a minor course correction it liked to start into its cornering lean so you needed to pay more attention to the wheel. The tabs corrected that tendency during small turns or corrections. I used to run with a friend who had a similar boat who refit a duo prop and a big block chevy and it worked so much better than his old standard O/D setup. We went to Catalina Island together a lot from the marina we slipped at, about 28 miles or so accrossed the ocean so I had a lot of open water time in both boats.
Bill

 

[QC]

Re: Trim. Speed, and Turning

Bill,

Take a reread. He doesn't have tabs. I do, but only mentioned as a reference . . .

 

[old school 65]

Re: Trim. Speed, and Turning

Am I missing something. I am very new to boating. I got a sea ray 205 sp and I never have had to adjust my tabs in a turn. Of course I have a whopping 9 hours on the boat (got the boat at the end of august and bam rain). Anyway, should I adjust my tabs in turns. I do lower my power in turns and I do get off plane in turns slightly. I have not noticed any listing in turns.

 

[QC]

Re: Trim. Speed, and Turning

Old school,

Welcome to iboats! This is a great place for new boaters.

So that we don't keep confusing this thread (me included), let's try to keep it on BSMan's issue. The discussion is about drive trim in turns, and/or possible eccessive listing in turns, not trim tabs . . . Personally, I know of no v-hull that does not list in turns unless it is not on plane. I have messed around with opposite tab application during high speed turns and it is a lot of fun. I do not recommend it though as it is very confusing, can be unsafe, and you can easily blow the main tab breaker if you're not careful.

You should do some searching through this section and the Mercruiser I/O sections. Lots to learn there. Again, welcome.

 

[JasonJ]

Re: Trim. Speed, and Turning

The one thing I think you are not doing is applying more throttle. When you are driving a boat and initiating a hard turn, you should trim in a bit, and apply throttle. Its like riding a motorcycle in a way. You have to give some throttle when cornering a motorcycle or you will fall over. In a boat, you have to increase throttle when in a hard turn to maintain speed and attitude. The boat is supposed to heel in when turning, and the resistance of the turn will cause the boat to lose speed and feel sloppy. When you give it more throttle, the boat will feel more secure in the turn and be more responsive because the bottom is being planted due to centrifugal force. You have to experiment, but you will feel it when you do it right. Just trim in, turn, and give it more throttle. You will feel the hull plant itself, and the turn will be smooth and fast. Good luck...

 

[Zackman]

Re: Trim. Speed, and Turning

QC, thanks for the clarifications to the others.

Maybe "listing" isn't the correct term. Perhaps it would be better described as a sudden and hard jerk. This happens well into the turn as I am turning the wheel more and more, there is is sudden hard jerk at the stern. Like I previously said almost like a 500 pound man just jumped to one side of the stern.

 

[QC]

Re: Trim. Speed, and Turning

BSMan,

Still sounds to me like the sudden "lifting up" that I described in my #2 post. Does it fall back down, or unjerk if you bring the wheel back a little?

Also, I will second what Jason says and add a little. When I learned to drive a boat I was taught when entering a hard turn to back off the throttle, trim in, crank the wheel and then add some power back in. This sets the bow into the turn, and then the power helps bring the stern around and may get her to slide a little. If you simply crank the wheel progressively harder, my boats have all stood up (or jerked down on the inside of the turn) uncomfortably at some point. One side of me wants to say "just don't do that anymore", but of course I haven't felt your exact sensation and there may in fact be something wrong. I just can't imagine what it could be . . . Is there an experienced boater you know who could go for a ride?