Riva Iseo inspired build

Discussion in 'Boat Design' started by Daniel79, Aug 11, 2016.

  1. Daniel79
    Joined: Aug 2016
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    Daniel79 Junior Member

    Hi everyone,
    Brand new to the forum so please accept my apologies for stupid questions and ill used English (I'm from the Netherlands).

    I'm planning on building a boat. Have been looking at the classical designs for quite a while but they are all a bit to tame (runabouts from Glen-L) or not practical enough for use with my family (like a proper gentleman's racer). Need a minimum of 4 seats.

    So I would like to build a cold moulded mahogany boat of which the design is rather similar to the beautiful ISEO by Riva.

    But now the big question: where do I get the plan for the hull design? There are some older plans out there of the aquarama for instance. But the ISEO is just very new...

    Any thoughts on this would be very much appreciated. As well as all the tips and warnings that you guys can give a man wanting to commence such a daunting task.

    With kind regards,
    Daniël.
     
  2. kerosene
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    kerosene Senior Member

    Just to gauge how reslistic idea you have about the project please answer two questions:
    1 what is your (even super rough guess) idea of the budget for the whole boat including all tech, harware and engines
    2 what is your guestimate for build schedule timeline

    Also the aquarama plans on web are good for making a scale boat but not for a real boat. Their accuracy is qustionable and unlike real plans they don't provide info on how to build the boat.
     
  3. daiquiri
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    daiquiri Engineering and Design

    Riva Iseo costs approxim. €350.000 if bought from Riva.
    To get an idea of what will it cost you to make it on your own to a similar standard, you should double that number.
     
  4. Daniel79
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    Daniel79 Junior Member

    Hi Kerosene,
    Thanks for your reply. Good to know that plans for a scale model is not accurate enough and provide to little information on the actual built.

    Budget for the boat roughly €70K. (30K for the boat itself, 40K for engine and hardware.) Single engine 350-400 BHP.
    Time wise I think I need 3500 to 4000 man hours (about 8 years) Building the boat at home in a dedicated shop.

    I have ample experience in wood-and metalworking. Also familiar with electronic's and mechanical engineering. Just never built a boat. But if you're gonna do it, than better do it right I always say.
     
  5. Daniel79
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    Daniel79 Junior Member

    Hi Daiquiri,
    You are right. A real Riva is expensive. Up from €280K as far as I know. Bulk (1500-2000 man hours)of this amount is in the labour costs but I don't want to build a real Riva.
    I don't share your estimate on what a homebuild Riva would cost. Why double it?

    Anyway. My boat should have the same feel and lines as the Iseo but not down to the centimetre. Big difference for instance is the material. I want to use wood (cold moulded with epoxy), Riva uses GRP. Also I want my boat to be about 21 feet. This is shorter than the Iseo, I know. But this is due to the size of my shop...

    I will upload a few design ideas shortly.
     
  6. daiquiri
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    daiquiri Engineering and Design

    Because I have seen people (4 of them, to be precise) who are professional woodworkers and metalworkers but with no experience in boatbuilding undertake the enterprise very similar to yours. I have been directly involved in 3 such builds, 1 as designer and the others as a consultant and supervisor.

    It will be a continuous and time-consuming learning curve, you will understand what it means when the gross job has been done and you start doing the detail work. The finished boat structure (framing and planking) will cost you some 10-15% of the total time required by the project and 15-20% of the total cost. All the rest will be details, details and more details - an incredible and endless number of small details. :)

    Of course, it all depends on the level of finishing you want to arrive to. If you want to arrive to anything similar to the Riva-quality finishing (http://www.mennyacht.com/yacht-models/riva-iseo), be prepared to leave your soul in every single piece of it.
    Otherwise, you have to make it firmly clear to yourself when shall be the time to say "that's enough - the boat is done", and stick to that decision. :)

    The next reason for the high price is that you will be a small buyer of any single component of your boat, be it mechanical or electrical. Hence, the price you will pay for the equipment will be 30%-50% and in some cases even up to 100% higher than the price a professional boatyard gets from their suppliers. It is a matter of market scaling and supplier's expectations of future profits.

    Why am I saying this?
    Because the worst thing that can happen to you as a boatbuilder is to start pouring your money into the project and then run out of it long before the boat is done. If that happens, you are left with no money and no boat. This forum is full of sad stories like that. Some people have lost their wife and house along the way. This is not to scare you, but to make you aware of all the possibilities, even the ugliest ones.

    8 years is a very long time. You even might change your idea about your ideal boat 8 yrs from now. Will you have the determination and stamina (both psychological and physical) to carry it on over such a long period? Does your family agree with your intents? You will need their support too.

    Once you have visualized and understood all the adversities, you can decide if you are up to the task. If the answer to all these doubts is an unconditioned YES, then go ahead towards your dream.

    The first thing to do is to make a rock-solid financial and building plan and to stick to it. Same for a well-defined construction plan and time schedule. Set-up the intermediate goals and milestones. Check often how does the build proceed against the milestones. If you start lagging behind the schedule, it should be your alarm bell. It will mean that 8 years might become 10, 12 or 15. And 12 or 15 years projected building time will most likely mean - game over.
    In order to keep control over the costs, make sure that the price of all the major components have been agreed with your suppliers and, if possible, fixed against major variations in the near future.

    If you feel discouraged after having read this - don't even start.

    If you don't - I wish you good luck and success. :)

    Cheers
     
  7. rasorinc
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    rasorinc Senior Member

  8. Daniel79
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    Daniel79 Junior Member

    Daiquiri,
    Thanks a million for your good advice. Good to hear that your estimate comes from real experience and not just a wild guess. I support your estimates on the percentages time wise and cost wise. And I believe my estimate on building cost will be realistic. But I certainly will take a far more detailed look into the costs and make a strict budget calculation.
    Fortunately I can order many parts through a well established dutch manufacturer of luxury tenders. As far as losing my house, I'm in the fortunate position that I do not have to take out a loan for the built. Certainly if I can spread the costs over a number of years. And to be honest, I'm not only building a boat so I can take it to the water. If that was the case I would just buy one. I want to physically make the boat with my own hands because I love making things myself. If the project for whatever reason fails. I will not hesitate to clear out the shop and scrap what I have made untill that point. The money I lose is experience I've gained and probably a lot of fun with my son and/or friends.

    The bigger question (and you have pointed that out really well, thanks for that) is how much time am I willing to spend? I'm still young (36) but have two young kids also. So 7 to 8 hours a week is a realistic amount of time that I can spent without 'neglecting' my kids and wife. That is the last thing that can happen. When my kids become older I might even have more time. But this is a VERY IMPORTANT factor. I don't know if I'm able to determine when enough is enough upfront. That will be a big challenge I imagine. I do take an enormous pleasure in the little details and finishing to perfection... Luckily I have a very supportive family and they are 'onboard'.

    Thanks also for the advice on breaking the big pla down to smaller milestones. It will be a lot easier to work from one small milestone to another instead of trying to oversee the entire build.

    So I do unconditionally say yes to your (very well thought through) questions.
     
  9. Daniel79
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    Daniel79 Junior Member

    Hope that the uploads work....

    side.jpg

    top.jpg

    These are two really fast made design ideas for the boat.
    For now I just took the drawings from the Riva website and have made the boat a little bit shorter (about 3 feet or 1 meter)
    This means that the two detached seats are still in place and also the curved bench like seat. I took out the two seats directly at the back of the detached seats in the font.
     
  10. Daniel79
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    Daniel79 Junior Member

    Here are the original drawings:

    original side.jpg

    original top.jpg
     
  11. daiquiri
    Joined: May 2004
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    daiquiri Engineering and Design

    Actually, I intended to say that your building costs might be up to double of Riva's building costs. And their building cost is definitely not €300.000 but probably something like 1/2 to 3/4 of selling price.

    But now I also noticed the additional info that your boat will be 21ft, instead of 27ft of the Riva Iseo. That changes things a lots, also because I believe that at the end you will not pursue the maniacal perfection and detailing of the Iseo boat in the photos from my previous post. So it will cost much less than what I previously said.

    The boat you plan to make is similar in size (and probably even in level of details) to Cherubini Classic 20 (https://www.ericwsponberg.com/boat-designs/cherubini-classic-20/) designed by Eric Sponberg, although Cherubini is a GRP boat.
    Mr. Sponberg is a member of this site, and is a very friendly guy always willing to help and share his knowledge. You can find his contact data here: http://www.boatdesign.net/forums/profile/eric-sponberg.html

    I think that it would be a good idea to ask him an opinion about the building costs of and man-hours required for a runabout of that size.

    Cheers
     
  12. kerosene
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    kerosene Senior Member

    8 yrs, you don't want to do it on a so so design. No matter what buy a real proven design instead of wasting the effort to get a crappy boat.
     
  13. Daniel79
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    Daniel79 Junior Member

    Kerosene, you are absolutely right. Wasn't planning on just whiffing a boat together from a sketch on a computer. But that is where it all starts. An idea, a dream and from there you need to go further. That's why I joined the community here. So You guys can warn me or point me in the right direction because you have a lot more experience. And so far it's been realy helpfull I must say.
     
  14. Daniel79
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    Daniel79 Junior Member

    Daiquiri, I think you are right. Have taken a look at your proposed design and I think I need to contact mister Sponberg. Thanks for this great tip. Will get back to this thread soon with the latest news.

    I also found someone close by that has a lot of experience in restauring and modifying boats. And he's very enthousiast about giving me a hand along the way. :)
     

  15. Daniel79
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    Daniel79 Junior Member

    It might become something like this:

    aangepast Sponberg.jpg
     
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