chop-nose up or nose down?

[Mello-Yello]

Yet another newbie-type question.

I can't seem to settle on whether to trim up or down when trying to get through rough chop. I had almost reached the point where it seemed smoother to trim down and punch my way through. Then last weekend, after 'bottoming out' a couple times and compressing my spine (I was actually 6" shorter by the time we reached the dock!) we tried trimming up. As you all know, doing this buries the rear in the water and really slows progress. I have to assume it looks real silly too, but after the dirty looks I got from my buddy, I just chugged along with my nose up. It seems as if I need to be at one extreme or the other when trimming. I'm a little concerned of getting "suprised" with a face full of water if I nose down too much, but then again, the boat is designed to handle this (shallow bow deck w/2" scuppers) and an additional 4" wing for water deflection. I'm not talking about busting waves, just that annoying irregular chop you get from NW swells being pestered by Southerly winds (you called it Mel!)

To save the questions; I have a 16 deg. deadrise at the stern and 30 deg. at the bow (20' aluminum w/offshore bracket)

I'm sure you've all been there and done that. I'm just wondering what you do.

M-Y

(gawd I hope this isn't a stupid question)

[Slugranch]

According to the experts, some where in the middle. If you are running with the bow down, you are using a lot of extra horses just to achieve that position. If you run in that position on a super flat lake, you'll notice the boat porpoising (taking little jumps, then nosing into the water and then another little jump). What you want to do is run with the bow up enough so the pointy part of the boat, the curve of the bow, is cutting the water but yet not getting the bow so high that the stern is buried or the water is being cut by the keel. It takes a pretty sensitive finger on the trim switch to find the best place to set the trim. Then if someone changes positions on the boat or you move anything that has any weight to it, you need to retrim for the shift in that weight. As your fuel tank empties, it will also affect the trim of your boat

I liked to keep the bow lower in chop to use the v to break the waves. It's a ballance. Play with your trim tabs until you find a sweet spot.

[Pilar]

Great question. I have just the one trip for experience. I ran the bow down and got a much improved ride over the normal 10 degree up ride.

You can tell when you have too much down because the boat gets 'sticky' and does not lift her nose quickly for the next bump.

I checked the settings after running into the NE wind Sunday returning from the Rockpile. I trimmed and trimmed for 10 or 15 minutes before I got a decent ride. On the trailer the port tab was down 1/2" and the starboard one maybe 1/8". Not much tab has a huge effect on the ride.

Looking forward to learning more.

[ 04-29-2003, 08:41 AM: Message edited by: Pilar ]

[Miss B Haven]

I think this depends on the boat, hull particular water conditons, loading, how much of a hurry you're in etc etc. As said above, play with it. :smile:

[Mello-Yello]

Is it uncommon to see adjustable trim tabs on an outboard w/adjustable trim? I'm running an offshore bracket and it seems quite obvious that having the motor further back is going tend to want to bury the rear at lower speeds. At lower planing speeds my motor is trimmed quite a bit to the neg. of center (regarding the trim guage on my dash. When I'm really running I can bring the trim way up to reach optimum RPM.

It just seems like having the prop pointed down in the rear is going to minimize fuel consumption compared to if I ran the motor level and adjusted trim tabs to bring the nose down.

[Mello-Yello]

Mmmmmm, wouldn't this be nice?

Otto Trim

I don't like auto anything :depressed:
When you have calm water try raising your motor and trim your boat with the tabs until you get an increase in RPM's. Get your motor as high as you can and trim your boat so it doesn’t porpoise. You can then throttle back and get better fuel consumption for the speed. Play with your trim in varying conditions until you know what it takes for the conditions.

[Mello-Yello]

Well, between everyone's input and doing some www research, it looks like adjustable trim-tabs are very much warranted, especially with my offshore bracket.

So, any suggestions on brands? I just left the Bennett page. I've heard of em before, and they certainly look like some good one's. Others?

[Miss B Haven]

Bennetts! Don't get the joystick control- everybody I know who has had them replaced with the individual rocker switches. Also- I would not have tabs without indicators, spend the extra. It can be very scary/dangerous to have the tabs down/boat out of balance and then hammer it up full tilt. YOu will be amazed at how fast you can dig a chine in and "right turn Clyde". Don't ask me how I know this! :shocked:
You can also learn where to set them before starting up on plane and where the optimum running spot is with the indicators.
Only another 1 1/2 boat bucks I think ! :grin:

Listen to Mel! Somehow my brother’s tabs got put into the port full down and the starboard level position and he almost rolled his 18' Glassply.

[Popeye]

One more thing guys...Don't use'm in following seas....Good way to pitch pole :shocked:

[ 04-29-2003, 10:37 AM: Message edited by: Popeye ]

[Pilar]

Popeye, that sounds interesting. What exactly is a pitch pole? Can you describe it for me?

[Popeye]

Pilar...The waves actually don't need to be that big if you are "trimmed" just a little too much. That's why it's best not to trim at all in following seas. With lots of experience, you can safely trim a little, but this takes years of experience...better not to though.

[Mello-Yello]

Popeye, by following seas, do you mean when the swell/wave is coming up on you from behind? (i.e. when you're returning to port on an ebb?). I can see how one could nose into the trough only to have the chasing wave pile up behind you. ugh!

What about motor mootching in reverse against the waves? Would one want their tabs in full upright position to help the boat raise with the wave?

Then, let's go back to my question.

:grin:

12"x9" tabs for a 20' boat? Bennett recommends a tab width equal your boat lenght (20' boat, 20" tab width) For the offshore bracket where one needs extra lift, they recommend 12" chord (fancy word for length) rather than 9". However, my dealer says 12"x9" would be plenty, possibly because I'm aluminum and am relatively light in the water AND I still have trim control w/my OB.

[Popeye]

MY...Anytime that yer in a possible "surfing" mode, yer in following seas. As far as "backing" into waves....not recommended. Some people do it occasinally, including myself, but again, "experience" and or a boat large enough to be able to withstand "A coupla big ones over the transom" :grin: As far as size of tabs, I'm no expert there

[ 04-29-2003, 02:40 PM: Message edited by: Popeye ]

[Miss B Haven]

Mello- Popeye is not talking about surfing as riding the backside in, he's talking about surfing surfing, just like on the board with your toes hangin over!
Lots of small boats with big engines (high power to weight ratio can and do ride the backsides in. It takes a boat that will plane quickly and stay up on step at the same forward speed as the wave is making (what- 12 to 15 knots?)without going over the top.
Popeye is refering to surfing down the face of a wave, something you don't want to do, but will happen if you have a boat that gets caught from behind while under significant power. Don't ask me how I know this. :shocked:
Big white pig boats can not ride the backside in. You gotta slow down (maybe 6-8 knots) and let the waves roll under you. If you try to goose it the stern settles and before you come up the wave behind catches up and lifts the stern. Now you're facing down hill under full power right? Gets exciting real quick.
It's a real change in bar crossing methodology lemmee tell ya. If you ever get the big white pig (or just get to drive one across, don't learn it the way I did. At least I didn't get my feet wet but pucker factor was about an 8 1/2! :shocked:

[Mello-Yello]

Ack!
:shocked:
I haven't the testicular fortitude for that!
Now I'm gonna have nightmares....
:shocked:

[ 04-29-2003, 02:44 PM: Message edited by: Mello-Yello ]

[Threemuch]

I GARONTEE on a deep v boat you want to be bow down going into chop. Eats gas, but the front of your boat cuts waves way better than the back. I drag my tabs all the time because the fuel is cheaper than the chiropractor.

Caution: Only do this when riding into the swell. When riding downswell, lowered tabs will cause the boat to push a great deal more than if the tabs were retracted. This can be a dangerous situation!

Boat trim is an art, and more difficult the bigger the planing boat and the bigger the water. You will figure it out anew for each set of conditions.

KB

[edsr]

Ask me about pitch poling at the next TA meeting and I'll tell you a little story.

edsr

[SouthCoastStu]

That reference to the Tillamook South Hole reminded me of a story.

It was the first time I fished it ('93?). I was in a friends sled. We were tucked up tight against the outside of the South jetty. I looked over to see a sled that got to far out get picked up by a wave, launched ~10' out of the water, and do a 180 :shocked: . Both guys were ejected into the water when the sled slammed down [img]graemlins/1zhelp.gif[/img] The sled next to us plucked one guy out of the drink, and the other guy crawled back into the boat. Would that rate a 10+ on the old pucker factor?!

The strangest thing is I remember seeing the same guys fishing later that morning! Hardcore!

[Miss B Haven]

Diamondback- I was fishing inside along the North Jetty one day. Bar was ugly (and closed). It was bad enough that they didn't have mother hen sitting there keeping the boats from crossing- you'd have to be blind and crazy to go out.
A guy came out in a sled running along the south jetty and just kept going. I could not figure out what he was doing unless suicide was the point. The waves were way higher than the jetty and a major curl at the top. Looked like great surfboarding stuff. He got just past the end and cranked it around just as a big one came up over the wash rocks. He drove that boat up and then across the face of a big wave about 2/3 of the way up it until he disappeared around the jetty. He was heading back down the face as he disappeared. :shocked:
It looked like a bobsled going through one of those banked corners on an Olympic track! That boat had to be on a 60 plus deg angle at the apex of his turn. [img]graemlins/eek13.gif[/img]
I called the CG and reported what had happened but they didn't seem to concerned and never sent a boat out. Don't know if the tower could see him or not. Musta been one of those little "commercial" guys that run the screwed down rods there other wise they'd have sent a boat out (I hope). :whazzup:
I often wonder if that guy is still fishing or even alive.

[Mello-Yello]

Thanks for all the info guys. Tomorrow I'm ordering Bennett's Trim Tabs. I'll be going with the rocker switch and indicators too (Thanks Mel!)

I just finished installing an additional bilge pump (1,000 gph) to go with my existing 500 gph.

Let's see, what's next? Radar? Yeah right...

[Mello-Yello]

Well, it looks like you guys have already answered my next question. I will get the indicators! I can't imagine not having them, especially since I can't even look out the back to see what position they are in (offshore bracket).

My local boat dealer says the 12"x9" should work fine for my boat (12" wide, 9" deep..chord). Anyone disagree?

[Miss B Haven]

Pilar - you ever seen those Scot's playing that game where they toss a log? Not sideways, but where you pick it up straight in the air and toss it end over end? [img]graemlins/eek13.gif[/img]

A boat goes sideways and rolls, it's broaching. It goes nose down (or nose up) and end over end, it's a pitch pole (worth a full 10 points on the sphinctor scale)! :shocked:
Never did see a commentary from Ken on drogue use (to prevent these). :whazzup:

[Pilar]

Zooooiicks!

I'm thinking that if your boat is pitched vertical that the attitude of the boat is the least of your worries.

The wave that is making it stand on end is pretty high on the list of worries.

[Mello-Yello]

Good Grief! At a sphinxter scale of 10, you wouldn't have to worry about falling out of your seat...not with that much suction!
:shocked:

[Miss B Haven]

Actually happens a lot at the South Jetty in Tillamook Pilar. It's one of the weirdest (and worst) spots I've ever watched waves build on an otherwise normal day.
They lose a lot of boats this way there. Those suckers can suddenly pop up 20 feet high, straight up and down with a 5 foot curl on the top. Not very long (wide?) they can be less than 100 feet. If you're not paying attention you go from fine to in them in nothing flat! I've fished just south and in from them and watched (feeling might awed I nust admit).