Moving the Rudders aft

jspiezio · Post by **jspiezio** » Dec 15th, '07, 14:18

Need some input. Having a 31 Bahia Mar rebuilt from ground up. The yard wants to move the rudders to the stern, a la BlackFin 29. They want to do this to allow them to alter the angle and extend the wheels further aft.

he idea is the boat will trim better on its own. This boat will have a swim platform so I am not so concerned about the rudders extending past the transom.

Any input and comments are welcome. Looking forward to it.

Bruce · Post by **Bruce** » Dec 15th, '07, 15:07

By altering the angle, I take you mean the shaft angle. They are trying to "flatten" it out. Problem is if you are repowering with diesel, the current angle works well to utilize a prop that will allow you to extract the power from the diesel.

When you flatten, you decrease the size of the prop you can fit. This would be okay if your using high speed engines, 6000 rpm range. If you are using gas, then its a stretch but then you'll have no bite out of the hole and you may have to go with a 1:1 gear box.

Non of which is ideal for the 31 to spend any money on that type of modification.

Too flat or nose down you'll get the bow acting as a rudder. BAD to say the least.

Take the money you'll spend on the modifications and go to Atlantic City. You'll get the same odds of return on your investment.

The boat trims fine just the way it is.

CaptPatrick · Post by **CaptPatrick** » Dec 15th, '07, 16:03

JS,

To amplify what Bruce said, the yard is shooting you a load of bull crap. Ray Hunt had the technology available to use external rudders & didn't. Think there might be a reason?

Br,

Patrick

Harv · Post by **Harv** » Dec 15th, '07, 16:36

There was a 38 at my yard last year. The new owner wanted a rebuild of his motors with an increase in horsepower, new backing plates for the struts and the rudders moved to the stern. I watched as the yard owner took down measurements and fabricated new aluminum strut pads and new stainless brackets and rudders. When I asked the yard guy why the stern mounted rudders, he said, "I told the guy it wouldn't add any advantage and the guy said, it's what I want, and it's my money". From what I saw, the only advatange it created was a slight increase in under deck storage. The 38 has since been shipped across the pond and now resides in Germany.

In Memory Walter K · Post by **In Memory Walter K** » Dec 15th, '07, 19:59

You're making a big investment on that rebuild. Given your yard's first recommendation, If the boat runs, I'd launch it and run (not walk) to another yard. That's a Bertram 31 and it's PERFECT. Any changes are cosmetics. Don't screw around with performance diminishing "upgrades". I wouldn't trust them for what you want done. Walter

AndreF · Post by **AndreF** » Dec 15th, '07, 20:09

Walter is a wise man

JK · Post by JK » Dec 15th, '07, 22:28

I'd look for another yard with extensive experience in redoing 31 Bertrams. They are not complicated boats but there are too many good yards around with experience to choose a place who wants to move the rudders aft. It's a bad idea.

--JK

jspiezio · Post by **jspiezio** » Dec 16th, '07, 07:36

Thanks for the feed back. Most of it matches my gut reaction, and I appreciate it.

Brewster Minton · Post by **Brewster Minton** » Dec 16th, '07, 07:54

These are the best minds in the world on 31 bertrams. Go to another yard. Bruce, Capt Pat, Walterk have more combined years around these boats than anyone ,they are to be trusted.

Carl · Post by **Carl** » Dec 16th, '07, 08:29

Lets look at this from another angle. The yard is recommending removing old rudders and ports, seal holes. Fabricate and install new custom rudder assemble and install on the transom. Remove and repair strut area , fabricate new struts and install back further. Rework the shaft log, make and install new shafts.

This is to make the boat trim out better?

Okay...how much better would the boat trim out? Does the boat trim out badly now, if so what about Trim Tabs? Your not sure about the regular tabs and want cutting edge, something different try those little wedge ones that come straight down.

Can I ask what you asked the yard to do? Are you trying to squeeze more top end out of the boat before she gets all squirrelly? That may be the only reason I could see going thru so much effort, even then how much faster could you go?

I think the yard may be going for different, not neccessarily better.

dougl33 · Post by **dougl33** » Dec 16th, '07, 08:50

Waste of time and money.

What are you putting in for engines?

jspiezio · Post by **jspiezio** » Dec 16th, '07, 10:06

What are you putting in for engines?

Yanmar 315s

Can I ask what you asked the yard to do? Are you trying to squeeze more top end out of the boat before she gets all squirrelly? That may be the only reason I could see going thru so much effort, even then how much faster could you go?

Bought this boat in rough shape.The boat is literally a complete rebuild. The hull was gutted, realigned and braced, then all new stringers and bulkheads were installed.
The intention is to create a new deck with no motor boxes. By lowering the YMs it will be possible to create a bridge deck instead, similar to a 31 Cruiser setup, like Finest Kind. This bridge deck will have a now fairly common L-shaped setee. All to make the boat more family friendly. The swim platform is on there for the same reason.

This boat will fish sometimes, but I run another boat that we fish pretty hard offshore, a Blackfin 32 FB, so we want to make this very family friendly. I like being able to pick your guys brains about this stuff, since you know more than anybody else about these boats. Been lurking for quite sometime.

Charlie J · Post by **Charlie J** » Dec 16th, '07, 10:31

where on the island are you located

jspiezio · Post by **jspiezio** » Dec 16th, '07, 10:51

where on the island are you located

West Islip

Over the years have had two B25s, two B31s, a B38, and a B42 in the family. Have had lots of other boats in between, but always seem to gravitate back the B31s. Just fantastic boats that look great with lots going for them. And they are full of memories for me.

I remember when I was 11 yo, I spent every day of my summer vacation on our then B31 SF with my dad and brother (Not to mention the time spent while school was still in session). Landed my first mako that year, 315 lbs, still hanging in my office.

Harv · Post by **Harv** » Dec 16th, '07, 13:58

cwj wrote:where on the island are you located

Sounds like a road trip.
If you want to take a ride count me in.

Harv · Post by **Harv** » Dec 16th, '07, 14:11

jspiezio wrote: The intention is to create a new deck with no motor boxes. By lowering the YMs it will be possible to create a bridge deck instead, similar to a 31 Cruiser setup, like Finest Kind. This bridge deck will have a now fairly common L-shaped setee.

There was a boat in the Hamptons not too long ago where the owner built up the helm area to accomplish the same effect. I also had ideas of making the deck so that the boxes would be eliminated. The two major drawbacks to this approach are, you would then have either a very sharp steep climb into the forward cabin or a long gap at the bulkhead to accomodate a longer, less steep stairway into the cabin. Secondly, you would probably change the center of gravity which could have an adverse affect on the ride quality.....and these bahia Mars ride just fine as is. Besides, with only 2 berths in the cabin, the engine boxes make a nice place for people to sit or lay out, especially when covered with cushions.

The only way to effectively get your shaft angle reduced enough to mount the motors lower in the hull would be to add prop pockets. These modifications are nothing more than wasted money. There are so many other things that can be done to these boats for the amount of money your modifications would require.

jspiezio · Post by **jspiezio** » Dec 16th, '07, 14:35

CWJ and Harv, would love to have you guys see the boat when it gets up here. Right now she is in Florida at the yard. Will post some photos for you guys.

She will be spending some time in Montauk each year, so it won't be a bad trip for you Harv. CWJ, you can see her when she is here in WI. Unless you prefer taking a ride out east.

Carl · Post by **Carl** » Dec 17th, '07, 07:45

Sounds interesting, love to see the end results so please keep us posted.

Harv, moving the strut aft a foot would allow him to reduce the shaft angle without pockets, but I'm inclined to think it would not be enough to compensate all the additional work involved.

ZeroCavity · Post by **ZeroCavity** » Dec 17th, '07, 11:57

jspiezio : Is your boat @ Carl's in St.Pete. ??? Is that is the case , I saw your boat and I will post photos of what you are talking for everybody to see.

jspiezio · Post by **jspiezio** » Dec 17th, '07, 12:41

Absolutely ZC. I did not want to post the yards name. Please if you have do post. I have several from March that show the new stringers installed. I will try to get these up here as well.

ZC, does Carl do some incredibly beautiful work, or is it just me?

I took the liberty of forwarding your photos of Paola to my B-in-law in Chicago. She is so pretty I couldn't help myself. That is his absolute dream boat. Good luck with her.

JP Dalik · Post by **JP Dalik** » Dec 17th, '07, 14:02

If its that big a project cut the transom out and make it a 33. If your gonna make it different might as well go all the way.
Recess the Tabs, standard rudder layout just further aft and lower shaft angle. Its a win win.

Carl · Post by **Carl** » Dec 17th, '07, 14:39

If this was recommeneded by Carl, I'll take back my words.

jspiezio · Post by **jspiezio** » Dec 17th, '07, 15:01

sim wrote:If this was recommeneded by Carl, I'll take back my words.

No need at all for that.

It seems like Carl has two different types of B31s moving through the shop. He is retoring some as close to stock as he possibly can. He is also doing some very custom things on those boats where the owners are willing to deviate from the specs, while maintaining the original spirit of the boats. In our case we were willing to alter some original specifications after seeing how other boats with similar alterations have performed.

But I have to admit moving the rudders and changing the shaft angle have been by far the most radical, and to me and my dad the most difficult to agree to. We have never really had a complaint about B31 handling or performance, but maybe we just didn't know any better. Shoot, I even liked the wet ride when I was a kid.

I tried to post from Flickr and that didn't work, so I think I will be opening an account at photobucket so I can get some shots up here for you guys to see.

Sean B · Post by **Sean B** » Dec 17th, '07, 18:28

.
.
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Carl is not afraid to chop into a boat. Check out this article about what he did to a B33 Cruiser. The results sound good,
especially if you have the B33 FBC with the teeny little cockpit, but it still gives me the creeps...
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Harv · Post by **Harv** » Dec 17th, '07, 20:18

Stretching a boat is nothing new. Back in the 80's I used to keep my little boat in the Hamptons at Scopinich's boatyard. The Skopinichs are the same people that make the fibeglass Columbia II's, and the wooden Columbias before that. One of the sons now builds the Skop35,an express fisherman, and also the Skopinich fighting chairs and accessories.
Anyway, during the 80's, Mario,(the Old man), did stretches on 2 boats that I know of. One was a 36 Topaz that was stretched to 39 feet, and another was a 54 Hatt that ws stretched to 57 feet. Mario would cut the transoms off in a zigz zag pattern. Bolt up a mold, lay in new stringers and lay up the rest. The only thing changed was the length of the boat. Props, shafts, and rudders were all left in the original locations. Mario didn't add more than 3 feet because he said longer extensions would have required the need for changing the running gear geometry and location. He must have known something. The owners were happy, and both boats got 2 more knots at cruise and WOT.

Harv · Post by **Harv** » Dec 17th, '07, 20:23

jspiezio wrote:CWJ and Harv, would love to have you guys see the boat when it gets up here. Right now she is in Florida at the yard. Will post some photos for you guys.

She will be spending some time in Montauk each year, so it won't be a bad trip for you Harv. CWJ, you can see her when she is here in WI. Unless you prefer taking a ride out east.

Any trip is longer for me than for Charlie. The boat is in Freeport, but I live in Brooklyn.

jspiezio · Post by **jspiezio** » Dec 17th, '07, 22:02

JP Dalik wrote:If its that big a project cut the transom out and make it a 33. If your gonna make it different might as well go all the way.
Recess the Tabs, standard rudder layout just further aft and lower shaft angle. Its a win win.

I liken what Carl is doing to what classic car afficionados call a "Retro Rod". You completely update the brakes, suspension, and drive train. But your still riding in a 396 SS convertible. If you cut the hull and lengthen it, now you've changed the heart and soul of what makes the boat so great. And then its not a 31B anymore.

Harv and Sean- I get the willies from the idea of cutting the hull like that. but I know that commercial guys have been doing it in wood, fiberglass, aluminum, and steel forever. If you read National Fisherman they seem lengthen, widen, and heighten their boats every season. I woudbe very, very wary.

jspiezio · Post by **jspiezio** » Dec 18th, '07, 14:58

http://s254.photobucket.com/albums/hh97 ... 31_photos/

some shots from this spring. Will get more posted up here soon.

jspiezio · Post by **jspiezio** » Dec 18th, '07, 15:48

Harv wrote: There was a boat in the Hamptons not too long ago where the owner built up the helm area to accomplish the same effect. I also had ideas of making the deck so that the boxes would be eliminated. The two major drawbacks to this approach are, you would then have either a very sharp steep climb into the forward cabin or a long gap at the bulkhead to accomodate a longer, less steep stairway into the cabin. Secondly, you would probably change the center of gravity which could have an adverse affect on the ride quality.....and these bahia Mars ride just fine as is.

The pictures show how we addressed this issue. The forward cabin passage has been shifted to the port instead of center. This alleviated some of the issue of steep descent and awkward gaps.

The bridge deck is less than 8" above the cockpit deck. The engines mounts were all lowered when the stringers/bulkheads were recreated. This also helped with the shaft angle issue.

I rode on a B31 BM that had a similar arrangment. The captain reported an increase of almost 6 knots at WOT, and a little over 4 knots at cruise, with the same powerplants he had before the adjustmentt. The boat ran just beautifully. The boat is used as a tender on a megayacht. The captain said running her is the best part of the job.

John Swick · Post by **John Swick** » Dec 18th, '07, 17:41

I got to get to his shop next time I'm down that way. Having seen pics of some of his other work I liken him as a sort of 'Chip Foose' of B31's.
JSPIEZIO, is there a Head planned for this project ?

jspiezio · Post by **jspiezio** » Dec 18th, '07, 17:57

John S wrote:JSPIEZIO, is there a Head planned for this project ?

According to Carl there will be! It looks tight but he says trust him. He has had a very free hand on this boat. He wanted the side exhausts to alleviate back draft of fumes. Which works for me because the women in the family don't love the smell of diesel the way the men do.

If you look closely you can see the new struts mounted.

[img][img]http://i254.photobucket.com/albums/hh97 ... 5_0_BG.jpg[/img][/img]

Carl · Post by **Carl** » Dec 19th, '07, 07:48

Looks like a few simple modifications to keep boat going...LOL

A ground up job for sure. I guess as long as you keep us posted we will all be learning on this project.

If you had decided to add a foot or two to the 31 you could have called it the longer version of the 31, then watch the reaction on people faces.

Yes it is a 31 Bertram...but I need a 33' slip as its the longer one.

ZeroCavity · Post by **ZeroCavity** » Dec 19th, '07, 08:28

Photos taken @ Carl's.
This are the famous transom rudders.

jspiezio · Post by **jspiezio** » Dec 19th, '07, 10:33

Thanks ZC.

I don't think any of those are my hull, we do not have under water exhaust as shown. I like to hear the engines.

Harv · Post by **Harv** » Dec 19th, '07, 10:37

ZeroCavity wrote:Photos taken @ Carl's.
This are the famous transom rudders.

Actually looks like a nice well thought out installation. I just don't understand the need for the integrated platform just to hold his tool box. :-D

In Memory of Vicroy · Post by **In Memory of Vicroy** » Dec 19th, '07, 10:53

A bunch of us rode on one of Carl's B31s at the FLL show a few years ago, the one with the all white interior...the underwater exhaust sprays water up at idle through some releif holes, sort of annoying. Maybe he has modified it since.

Think it had 315 Yannies and the sucker was fast....

UV

Carl · Post by **Carl** » Dec 19th, '07, 11:13

Come on Harv, you know the platform is integrated not to hold a tool box.

The platform is there to hold the tape on that "Custom Tool Box Pedestal". I think Randall made it from a block of wood cause if you look closly you can see the grain.

Joking aside, I guess Aft Rudders are not a theory as he seems to be maken them. They do look good, nice and clean.

jspiezio · Post by **jspiezio** » Dec 19th, '07, 11:51

sim wrote:Come on Harv, you know the platform is integrated not to hold a tool box.

The platform is there to hold the tape on that "Custom Tool Box Pedestal". I think Randall made it from a block of wood cause if you look closly you can see the grain.

Joking aside, I guess Aft Rudders are not a theory as he seems to be maken them. They do look good, nice and clean.

Yeah, Carl offered a custom "Custom Tool Box Pedestal" sculpted by Randall, but we need to keep this project under budget!

jspiezio · Post by **jspiezio** » Jan 18th, '08, 20:45

Dad is heading south next week. Will check on his special project over at Elite Marine. Carl says the progress has been tremendous and sees her floating this summer! He also has relayed several offers for the boat that would result in a tidy little profit if dad decides to go that way.

Very excited to get some pics up, I am planning a short trip in Feb so I can see where she's at myself.

ZeroCavity · Post by **ZeroCavity** » Jan 18th, '08, 21:13

PLEASE !!!!! Photos here as soon as posible !!!

scot · Post by **scot** » Jan 18th, '08, 23:30

Who manufactures the external rudder units?

jspiezio · Post by **jspiezio** » Jan 18th, '08, 23:55

I'll ask Carl.

ScottD · Post by **ScottD** » Jan 19th, '08, 09:09

I work just across Salt Creek from Elite Marine and stop in to look over the 31's in progress. I don't think Carl is doing any more underwater exhausts, but the external rudders are popular. On the 28's it really helps when putting in the diesels, not a lot of room to work with. Carl's not big on pictures of his work usually, but if he doesn't mind, I take pic's of all his projects. Most of the guys that looked @ shooter in FLL didn't get a good idea of what Carl does with the interiors, that project didn't include any upgrades, and the interior is what makes his work stand out above everyone else in my opinion. Everything he does is first class, but it don't come cheap, but nothing in boating does.

ScottD

DRIFTER31 · Post by **DRIFTER31** » Jan 19th, '08, 23:17

I saw aguy strech a searay33 flybridge to 36ft and did a great job on glasswork etc.... only problem is it floated to high and was top heavy.

bertram31.com

Moving the Rudders aft

Moving the Rudders aft

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