Boat extension

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shipshape

Senior Member
Joined
May 23, 2010
Messages
117
Location
Australia
Vessel Name
Eliza 1
Vessel Make
Halvorsen 42 Pilothouse
Hoi,

I saw a boat in a marina in Sydney ... with an extension built on the duckboard. It seems they cut the transom ... As my cockpit is a bit small (see the last photo), I thought it was a good idea, probably an expensive one ....
Would it upset the strength of the hull?
Will it be strong enough on just supports?
what does the forum think about this?
Thanks.
Erik
 

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Recently a fellow TF member was so kind as to give me a great tour of Sidney Harbour. From that tour, it would seem that for the protected waters in the Harbour, recreation and partying utilizing the addition would be enhanced. But in open water, a large following sea could board the extension and possibly tear out some attachment bolts and allow water into the boat. You are right, it is good looking and likely fits the owner's needs perfectly.
 
My knee jerk reaction was to say YES ......the transom was much weakened but transom doors are almost as bad. Not being outboards not much transom strength is needed but one would think the transom would tend to keep the whole boat from twisting. In this case if the area at the bottom of the transom cutouts is/was strengthened perhaps it's plenty strong enough.
As for water ingression I see many many fast powerboats that do'nt even have a transom. They look more like a Jacuzzi than a boat and I would think a stern sea could easily poop one of these boats and possibly cause a sinking .........but I've never heard of it happening. One thing I can say w reasonable conviction is that this boat will be hard to sell. Not recommended for all of the above at least.
 
Erik, much as it would be tempting to do the above, like most have said, it would not be good for re-sale. It would limit the boat to sheltered waters only I suspect, as others mentioned. The only way to go is to actually add about metre to the hull, which can be done, but EXPENSIVE. I used to lust after a craft of which there are quite a few in our area, as they were very popular, called the Mariner 39, sedan, however, although a beautiful looking boat in many ways and a lovely layout, with plenty of saloon volume, shared the same problem of a too short cockpit. So much so several owners in this area added a metre to the hull (calling it a Mariner 44), purely to lengthen the cockpit. Made the cockpit a much more useable outside area...but at what cost..? I also wondered about the integrity of the join, but I guess epoxies/construction techniques being what they are, it could be done strong enough.
Here is a nice original one without the extension.
Information on Mariner 39' Flybridge Cruiser
 
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Maybe not so clear on the pictures, but the "holes" in the timber frame are all glassed .... not sure if that was clear ..... I guess the portholes for the mooring lines are not necessary, I agree about the transom door not giving much strentgh either ....
Peter, how are you? Long time no hear ? Still at same marina? We are in HopeHarbour now.
 
Yep, still at Horizon Shores, Erik. Actually I have often wondered how you two were getting on with ShipShape, and I thought next time we are going out we would call you and see if you were possibly going to be out there somewhere. We should try to set up a rendezvous sometime...? What do you think?
 
I like the idea. It looks as if they exstended the swim dech a couple of ft. The original look to be very small. Since the areas are glassed in not much water should get in.

One of the reasons my wife liked the Eagle is the 10 x 14 ft stern deck that she uses alot year around being enclosed.
 
There is a guy in Vancouver who has done Uniflyte 42s, to 48, then they look just like the aft cockpit 48s. There are 2 extended and one original 48 in our YC. You can tell them apart, but only if you know what to look for. Likewise, C&L47 (Sea Ranger) became 50 or 52. Those you can tell have an extension by looking at the teak boards on the cockpit floor. Otherwise they look original.
Point is, if done properly, no problems. The biggest issue is moving the props and rudders back. Some don't bother, and accept the consequences in oddball handling.
 
It's difficult to determine from the pictures where the aft mooring lines are cleated inside the new addition, but it appears that any significant strain on those lines is going to put a lot of lateral force on the extension.
 
Greetings,
With all due respect to the fellow in Sydney, his extension appears to me to be an add on billiard table. Very nicely done though. One could use the hawse pipes as pockets if one had enough spare balls...
 
That transom extension is pretty work and looks like it would be OK for dock sitter or mellow bay waters. Rough ocean water, especially fairly close duration tall following seas with wind-crest tops would tear that boat a new A-Hole. Maybe sink it! :facepalm:
 
Art, couldn't the same be said of many swim platforms?

Meanwhile, keeping the platform folded:

img_82983_0_674951fcb770746c461a6f2f5f80fbc6.jpg
 
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Art, couldn't the same be said of many swim platforms?

Meanwhile, keeping the platform folded:

Yes, Mark it could.

But not all swim platforms will rip off even in heavy following seas due to their good fastening, supports, drain holes; and their being not too wide off transom. As well as those that could fold up against transom (like yours) and fasten tightly for sea travel. Not that I’m saying the fastening is not good or support under applied, but, the addition pictured in beginning of this thread looks very oversized as compared to an 18" to 24" flat platform with drain holes.

I admit that in years past I did not have any swim platform and having one now makes me think twice as to its actions/reactions regarding heavy following seas. At very least if it held firm it would probably make handling the boat more difficult.

My dad would have had a conniption-fit if he saw my Tolly with its swim platform. Then again few pleasure boats encounter big following seas such as we used to at times in the Atlantic. Yup!! - - > those were the days. I sure have no heavy seas deep in the Delta... just R&R, cruiseing, swimming, and playing with our little canopy covered speed boat; i.e. comfortable pilot stationed four comfortable seater 50 hp O/B tow behind runabout!

When we retire and get a 48' Tollycraft outfitted for costal cruising I highly doubt I will leave a swim platform in place while doing ocean travels. Be cool to figure out how to redesign it so it can be easily and securely out of the way while quick and secure to put into downward position!

God we love the water, can tell you do too! Cheers!! Art
 
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Boat Extension(Ranger 40)

That boat,named "Lone Ranger",has a full page advertisement for sale in the April edition of Australia`s excellent,and free, "Afloat" monthly magazine,(Afloat.com.au). It was a Ranger 40 before modification, has twin V6 turbo 420hp Yanmars replacing 160hp Volvos,and a claimed top speed of 22 knots (feeling faint thinking about fuel burn and range). The advert invites offers and claims a Surveyor valuation of $300K. The extension to 44ft is said to involve glass and frames of stainless steel and teak.
I`m not sure the glass transom will catch on with manufacturers.
BTW,I`m hoping 'Afloat' prints a letter I recently submitted to 'The Editor', drawing the attention of Australian boaters to both the Forum,and American Diesel.
BruceK. Sydney Australia.
 
Yes, Mark it could.

But not all swim platforms will rip off even in heavy following seas due to their good fastening, supports, drain holes; and their being not too wide off transom. As well as those that could fold up against transom (like yours) and fasten tightly for sea travel. Not that I’m saying the fastening is not good or support under applied, but, the addition pictured in beginning of this thread looks very oversized as compared to an 18" to 24" flat platform with drain holes.

I admit that in years past I did not have any swim platform and having one now makes me think twice as to its actions/reactions regarding heavy following seas. At very least if it held firm it would probably make handling the boat more difficult.

My dad would have had a conniption-fit if he saw my Tolly with its swim platform. Then again few pleasure boats encounter big following seas such as we used to at times in the Atlantic. Yup!! - - > those were the days. I sure have no heavy seas deep in the Delta... just R&R, cruiseing, swimming, and playing with our little canopy covered speed boat; i.e. comfortable pilot stationed four comfortable seater 50 hp O/B tow behind runabout!

When we retire and get a 48' Tollycraft outfitted for costal cruising I highly doubt I will leave a swim platform in place while doing ocean travels. Be cool to figure out how to redesign it so it can be easily and securely out of the way while quick and secure to put into downward position!

God we love the water, can tell you do too! Cheers!! Art

I think a folding platform is pretty neat also...but the average, well designed swim platform sheds water well enough that I don't think they are an issue. In seas that jeapordize that connection...I have a feeling the main boat might be in as much danger. If in doubt...for that once in a lifetime storm...you could always have a few weak links in it so all or part breaks away. And make sure your transom is in good shape...;)

I've watch some big swim platforms in breaking waves in out inlet and like I said...the boat becomes an issue before I say any issues with the platforms.
 
Essentially this arrangement (on the boat at the start of the thread), is a glorified balcony off the back of the boat, is it not..?
 
I don’t see what the big deal is. It appears they extended the swim deck about a foot and raised it flush with the stern deck. What is the difference of extending the swim deck as many boats have done its just enclosed. As long as they increased beefed up the supports, and if you look closely at the detail/fit is done well. The surrounding boats looks to be go fast sun decks which are protect water boats. So what’s the big deal?

When looking at picture of boats I also look at the surrounding boats and landscape to get a better felling. We enjoy the Eagle stern deck year around especially in the summer with the 19 ft run about and 12 ft Livingston tied off the back of the stern. We been told many times the Eagle 10” X 14” back deck is on of the nicest features of the boat, which we did. However I wish the swim deck as about a 6” to 12” 1 ft wider.
 

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I think a folding platform is pretty neat also...but the average, well designed swim platform sheds water well enough that I don't think they are an issue. In seas that jeapordize that connection...I have a feeling the main boat might be in as much danger. If in doubt...for that once in a lifetime storm...you could always have a few weak links in it so all or part breaks away. And make sure your transom is in good shape...;)

I've watch some big swim platforms in breaking waves in out inlet and like I said...the boat becomes an issue before I say any issues with the platforms.

Thanks for input on your visual experience with swim platforms, PSN!

There was a near disastrous encounter due to unexpected weather and resulting sea conditions that occurred to members of my family upon approach to and during entry to Block Island inlet, 1970. I was not aboard that time but have heard the harrowing story many times since from the three that were. Dad and Mom passed from old-age in 2004/ 2007 respectively. My brother to this day will reemphasis caution toward the power of the sea due to that perilous encounter. Recount of all details to their story would take too long here... suffice it to say...

1. Atlantic Ocean, in New England waters, a sudden, unexpected squall/storm came up in latter afternoon
2. 38’ raised deck, 180 hp single Perkins diesel, incredibly well built and in excellent condition, semi displacement wooden sport fisher, with fully enclosed salon and wide single bench-seat on open fly bridge, hydraulic steering
3. In minutes the rather gentle long duration 2’ to 3’ rollers topped by light chop they had been running through for hours became 8’ to 12’ seas and visibility due to pelting rain dropped from miles to near zero... they had seen the jetty entry in the distance but were still some 2 miles from the inlet and completely lost sight; had to slow from 10 knots to whatever dad could do to keep the boat in correct trim and compass heading
4. After short time the wind increased to where horizontal rain felt like bb’s hitting your face and even larger waves became so confused in direction that as one broke over bow to splurge onto front of bridge and salon windows (luckily these windows were extremely thick, rather small and with enormous surround structure) there was another beginning to crest at some 45 degrees off starboard side of bridge.
5. Although boat was 13’ at bridge top there were waves whose very tops broke onto bridge. And, too often starboard beam waves would heal the boat so far over to port that the port salon windows and side of bridge would slap waves on that side.
6. This continued for what seemed an eternity (to them) and all three being on bridge could only hang on to the hand holds there and do best to not get thrown overboard.
7. Dad being a consummate aerial photographer in a spitfire plane as pilot and navigator from WWll, as well as a many decade seafarer who had a sixth sense for the direction being traveled was luckily able to hit the inlet square on the nose when they finally got to it. Visibility was in feet from rain and sea spray.
8. Due to outgoing tide and the high winds the inlet was filled with conflicting direction waves as well as in general a huge following-sea as the highest winds pushed right into the inlet’s snout
9. Boat made it inside to Block Island’s “Great Salt Pond” where conditions were still rough but nothing like the ocean. For near two hours dad milled around under power waiting for chance to anchor, or tie to a dock.
10. Storm subsided; wooden boat hull was racked and leaking profusely. Ended up at dock with emergency pumps aboard and hauled boat the next day. Two planks had somewhat sprung at bow stem and one amidships some two feet below waterline. Interior was a mess from tossed goods and every varnished joint in the boats gorgeous mahogany interior was racked (keel was laid in 1951, hull as well as expansive raised deck were built by Freeport Point Shipbuilders, NY., Interior was constructed by Brooklyn Navy Yard’s master carpenter., Boat originally built for and owned by a NY Harbor Pilot.
11. After repairs, they all cruised home from an immediately curtailed five week cruise they had only been a week into. Upon reaching dock in Camden ME mom turned to dad and blurted out... SELL the boat, you nearly got us all killed, I’ll never step foot upon it again! My brother said those were the first words she spoke on trip home (oh my poor dad!). Boat got sold and from it dad bought a Cessna plane to begin his “new” career as a private business aerial photographer.
12. Interestingly, according to my brother even with all the bad water they encountered outside the inlet, it was the following-seas and conflicting waves in the actual inlet that was most scary as dad would fight with steering and throttle to counteract the boat’s tendency to broach and/or get rolled or smashed into the jetty boulders by the steep, tall, close duration following-seas.

So... besides having been in some bad water conditions before myself, following-seas included... the rendition of that encounter is the reason I question what effect a swim step may develop in treacherous conditions of unusually violent following-seas.

Life is to be cherished. Boating, in more ways than one, can be a kick in the ASS!
 
Essentially this arrangement ...... is a glorified balcony off the back of the boat, is it not..?

Yes it is and I wonder how much he devalued the boat, regardless of what the surveyor says.
As far as the looks of the balcony itself - a very nice job. As far as the overall appearance of the boat with the extension - very dumb looking. Thats just my personal opinion and I'm sure others will think it is beautiful.

It would be nice to see what professional yacht brokers have to say about the valuation.
 
"Tony B-Yes it is and I wonder how much he devalued the boat, regardless of what the surveyor says. "
'"As far as the looks of the balcony itself - a very nice job. As far as the overall appearance of the boat with the extension - very dumb looking. Thats just my personal opinion and I'm sure others will think it is beautiful."

It would be nice to see what professional yacht brokers have to say about the valuation.[/QUOTE]

The Advert quotes Port Stephens Coast Guard (now called Marine Rescue) as saying "That has to be the prettiest boat on the port".
"Beauty is in the eye of the beholder".
Surely the effect of a following sea would be markedly less with a traditional latticed teak platform than the solid fibreglass ones; the water has somewhere to exit instead of welling up loading the platform and attachment points. BruceK
 
If you want a seaworthy boat you wo'nt have any of that truck on the stern. And if you want to extend the boat buck up and extend the whole hull. Get a longer WLL too.
 
That is without a doubt the most butt-ugly thing I've ever seen on a boat and I've seen a lot of butt-ugly stuff on boats.

There is a marine company in Bellingham that obtained the molds for a long-out-of production cruiser of about 45 or 50 feet and created a hull extension that allows an eight foot or so wide swim step--- swim platform really--- on top of it. This setup makes some sense but it is not a "porch" stuck on the back end of the boat. The hull itself is extended back some eight feet or so and the extension is integral to the hull structure itself. And the huge platform aft of the normal cockpit bulkhead is extremely functional---- most of the one's I've seen store a big RIB there.

But that's a whole different ball game compared to the "porch" in the photos. Regardless of the function or strength or potential problem in any sort of a sea, the design itself is attrocious in my opinion. The owner has taken what was an ugly boat to start with and made it laughable. It looks like something you'd see up on blocks in a trailer park. The only thing it needs to complete the picture are some pink plastic flamigos duct-taped to the raiing. Be fascinating to find out how this guy acquired his sense of aesthetics--- probably make a good PhD dissertation for a budding psychologist.:)
 
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I've seen a couple of these Menorquins on the East Coast. Nice boats, except for the strange looking back porch.
 

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That is without a doubt the most butt-ugly thing I've ever seen on a boat and I've seen a lot of butt-ugly stuff on boats.

Thanks Marin- I was beginning to think no one would tell it like it is on this one. They might as well add a tree fort on the top as a flybridge enclosure.
 
I've seen a couple of these Menorquins on the East Coast. Nice boats, except for the strange looking back porch.

IMHO - - >
That boat could too easily swamp and kill you in a tall, steep, close duration following sea resulting from high winds and strong opposing current of an inlet or other location. :eek:

Looks like the builders tried to copy the look of large "porches/landings" placed on mega yachts' sterns. Even the mega yachts could experience trouble in nasty enough open seas with those new-world stern platforms. On small boats I feel they are nuts... unless the boat owner is sure to NEVER get caught in bad enough seas. However, that word never, can never be fully counted upon! :facepalm: LOL
 
Re the Menorquins..........................

I would NEVER buy such a boat.
 
Re the Menorquins..........................

I would NEVER buy such a boat.

Now, Eric... That word NEVER is just too big to EVER fully discount. If someone freely offered you a few hundred grand $$$, but the one stipulation was - you must purchase a Menorquins with the cash... the word NEVER, in this instance, would go right out your window! Then you could sell that boat and be FOREVER grateful for the $$$$! My, what BIG words we throw around!! :whistling: LOL
 
Are the large open areas filled with glass or lexan?

Can't tell by the pictures.

Is that a for sale sign on the upper deck.

Inquiring minds.

Sd
 
Whlle I don't think hull extensions like the one on the Menorquin are particularly aesthetic I think if they're done right they don't have to affect seaworthiness. If the platform extension is indeed an integral part of the hull mold and is laid up accordingly or is spliced to an existing hull in such a manner that it becomes integral with the hull, I don't see it compromising the strength of the boat at all. Boarding seas will run right off and as long as the deck and hull are built to withstand the weight, what's the problem?

Fishing boats and tugs encounter situations where their decks are awash or inundated with water all the time with no problems assuming the boat's designed for these conditions. Ocean-going yachts encounter these conditions and the skipper of one once told me that the big aft platform behind the "garage doors" posed no issues at all even with following seas swamping them every now and then. If a boat like the Menorquin is properly designed and constructed--- and I have no idea if it is--- it is nothing but a scaled-down version of these larger boats so I wouldn't figure it would do any worse.

From the look of the boat overall it appears to be a coastal cruiser, not an open ocean boat anyway, much the same way a Grand Banks is a coastal cruiser, not an open ocean boat except under ideal conditions. So my guess is that, like the hull extensions installed by the Bellingham company I mentioned earlier, the Menorquin probably does just fine assuming good design and construction.

I don't care for the look of these platforms behind the transom but from the few boats I've seen with them they are certainly functional and add a lot of usability to the boat. Doesn't seem much different to me than the so-called "sea (or C) drives" used on some smaller sportfishing boats like SeaSport and the like, where a large motor well is attached or molded to the hull aft of a full-height transom. Gets the outboard(s) outside the cockpit altogether so there is no intrusion into the fishing space. Waves swamp in and the water runs out. No problem.

Here's the other side of the extension equation. A configuration of lobsterboat that is apparently growing more popular in Maine (didn't see any on Prince Edward Island) does away with the transom altogether. This in theory makes it easier to launch and recover strings of pots, although I had a couple of commercial lobster fishermen in Maine tell me the other year that the cutaway transom has resulted in more back injuries because of the way the pots are handled now. Regardless, following seas simply climb up into the boat and run back out again. And these guys go out when they have to go out as opposed to the typical yellow-stripe recreational powerboater who tends to tighten up the docklines when the wind starts climbing over 20 knots. If this boarding sea business compromised the integrity of the boat, I suspect the lobstermen wouldn't be using this configuration.
 

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Whlle I don't think hull extensions like the one on the Menorquin are particularly aesthetic I think if they're done right they don't have to affect seaworthiness. If the platform extension is indeed an integral part of the hull mold and is laid up accordingly or is spliced to an existing hull in such a manner that it becomes integral with the hull, I don't see it compromising the strength of the boat at all. Boarding seas will run right off and as long as the deck and hull are built to withstand the weight, what's the problem?

Marin

The problem is physics of weight - vs – general boat stability and steerage direction during times of very aggressive following seas. It's not that the back flat area won't drain, it is that as the cresting following wave slaps its tons of weight upon that area it will tend to shift the direction of the boat so forcefully that a dangerous breach could easily occur. Turbulent/confused following seas do not all hit the rear of boat in parallel with its direction, rather they often hit at all sorts of angles as compared to the direction a boat may need to hold. Sometimes a boat may need to hold a slightly angled direction compared to general direction of the following sea, in that case if the sea was aggressive the flat platform could be disastrous for keeping the boat stable. Transoms in general, with no flat platform, tend to shun the following sea’s direction changing thrust. That is why double enders are so great in accepting the following sea and easy to handle in following seas. Eric’s double ender would be a joy compared to most boats in a following sea.

These platforms will probably not be a problem – unless you get caught in a BIG and aggressive following sea. That’s the point I’m making.
 
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