Floating Restaurant

Discussion in 'Boat Design' started by Bahaman, Aug 17, 2023.

  1. Bahaman
    Joined: Aug 2023
    Posts: 4
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    Location: The Bahamas

    Bahaman New Member

    Hi All
    I'm wondering if any of you fine people would be willing and able to talk through some of the logistics of building a floating bar.
    I live in The Bahamas and I'm trying to put together a business proposal that would cover all the necessary aspects. I'm in the process of designing the above water aspect, but I'm not very well versed in buoyancy and stability.
    I've attached a photo of a currently existing floating bar I think has a good design that I would like to mimic. It's about 3000sq.ft on the lower level and an additional 1000 sq.ft on the upper level. I've estimated a total weight of 65-70,000lbs that needs to be floated.

    If anyone has experience in designing something along these lines I would love an opportunity to chat with you. Happy to compensate for the right person.

    Attached Files:

    willy13 and fallguy like this.
  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Good morning Bahaman - welcome to the Forum.

    A few questions - re your floating bar, do you intend to moor it in one spot semi-permanently in the Bahamas, or will it have to be able to undertake slow cruises with passengers / drinkers along the coast?
    A floating bar that has 3,000 square feet of deck area is approx 55' x 55', or approx 70' x 43' - either way, this is a pretty big boat to build!
    Where are you planning on building this bar - locally / nearby on a beach, or further afield?
    You will definitely need to have a sound appreciation of doing calculations / estimates for buoyancy and weights before you jump too far into this project.
    I hope that you do have (at least) a seven figure budget in US$ available for building this floating bar?

    We built a much smaller (40' x 16') floating bar here 20 odd years ago for a gentleman who had been accustomed to drinking in a particular beach bar here, but then they decided to go upmarket, and raise their prices.
    He was appalled by this, and wanted to offer them some competition - however beach front land here is so expensive (in the millions).
    So he thought about a floating bar instead.
    And we built him the good ship Rumpy Pumpy - here are a few photos.
    She had 2 x 50 hp high thrust 4 stroke outboard engines (she would do coastal cruises / parties for up to 40 punters on demand), and would park outside the upmarket beach bar, drop the bow ramp, and hang up a sign offering cheap beers - and the punters ashore rapidly deserted their upmarket establishment, and went to visit the floating bar, causing the bar ashore to lower their prices in desperation.
    She was very popular for a few years, but then circumstances changed (it is a long story), and she is now laid up ashore.

    RP at Mullins.jpg

    Rumpy Pumpy _0003.jpg

    Rumpy Pumpy _0004.jpg
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  3. Bahaman
    Joined: Aug 2023
    Posts: 4
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    Location: The Bahamas

    Bahaman New Member

    Hi Bajan
    Thank you very much for replying. That boat you built looks very cool, and I love the idea of sticking it to the "man" who's jacking up prices. The island I'm on is a similar situation where property values have gotten so high that finding a location for a restaurant has become impossible.
    So the plan is for the bar to be moored in one place for the majority of the time. Obviously it needs to be somewhat mobile at times (storms, off- season), but I think for the most part it will have a firm location and use a tug boat to move it when necessary.
    Space wise, we're looking at something along the lines of 60x40. Looking at the design of the boat we're using as inspiration the floating base is closer to 50x30 with a 5ft cantileverd overhang around all the sides.

    My idea is to use a barge (or a few formed together with steel framing) as the base. This in theory should give me enough buoyancy to handle the necessary weight. Two 40x10x5 barges should be sufficient to carry the weight (they would be rated to carry 37,000lb each for a total of 74,000lbs).
  4. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    What calculations have you done so far to assert that this will give you enough buoyancy? Have you done any rough buoyancy or weight calculations yet?

    Again, what calculations have you done so far to determine that they should be 'sufficient' to carry the weight'?
    If we assume a maximum loaded draft of 2' 6", then this gives you 2' 6" of freeboard on the hulls - which is not a lot really.

    Two of the above hulls at 2' 6" draft will have a buoyancy of 128,000 lbs, or 57 tonnes - this will be your load displacement.

    But you want to be able to carry 74,000 lbs (which is 33 tonnes) - this leaves 22 tonnes for the hulls (11 tonnes each).
    Is this enough?
    What material are you proposing to build the hulls with?
    And will you use the same material for the bridgedeck structure to join the hulls together?
    Where are you going to build this big cat?
    Have you access to a plot of land on the beach that you can rent for a few years (or longer)?
    A gentleman here has been building a 60' x 25' catamaran party boat on a beach here for the past 20 years, and he is still a long way from completion.

    The 33 tonnes mentioned about will have to include all the bridgedeck structure, superstructure, tankage for water (will a water tanker visit the bar occasionally to top up the tanks?), provisions / stores, crew and guests - how many people are you hoping to have on board at one time?

    Will the bar be moored to a dock, or anchored off a beach somewhere?
    If the latter, will you have a tender service to shuttle people to and from the beach?
  5. Bahaman
    Joined: Aug 2023
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    Location: The Bahamas

    Bahaman New Member

    Hi Bajan
    Ok, this is admittedly where my personal knowledge starts to come up short. Thank you again for taking the time to talk this through with me.
    My skills are more in the area of carpentry, I've built quite a few decks of this size or larger. So My rough estimates of weigh really only include the weight of the deck, supplies, and people. It's the whole keeping it afloat aspect where I need the assistance.
    I have a boat yard where we can do the work, it has all sorts of heavy lift cranes abs equipment necessary to launch it.
    For me the biggest hurdle would be getting the floating foundation built sturdy enough to move onto the wooden aspects of it. Once I have that aspect sorted I'm confident I can built out the deck part in a matter of a month or two.

    Talking to the guy from the boat yard here's what he can offer me that he has in stock. They are 7" high barge so that
    "I have a 30 x 10x7 raked Shugart along with two 10x40x7’s and two 10x20x7’s that gives you a deck of 30x50x7 with a forward rake or turn the raked 30 around to make the whole 30x50 square"
    This is much larger than I was initially thinking, but let me know what you think.
  6. Bahaman
    Joined: Aug 2023
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    Location: The Bahamas

    Bahaman New Member

    The plan is to have the restaurant moored in one location with shuttle boats to bring clients to and from, as well we would allow pull up traffic from private boats.
    The example we're using to base the build off of holds about 100 guests at any one time. There's plenty of local staff and provisioning available as the area is a highly popular tourist destination already.
  7. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    The difference with decks on land, and decks floating on the sea, is that you don't need to worry about if you have enough buoyancy to support your deck on land - the land supports it very well.
    So, as a first step, you should design everything above the deck level re this bar / restaurant - sketch it out on paper, or with CAD even - and start to tally up a Bill of Materials.
    And then calculate the weights of all the materials.
    And then add on the weights of all the consumables, and the weight of the 100 guests, and all of the crew (you could assume 180 lbs per person as an average weight).

    You want the barge to float level, so if it is a symmetrical shape, then the centre of buoyancy will be in the middle - and this is where you want your overall centre of gravity of the loaded barge to be. If you take moments (weight x distance) about one of the ends of the barge, then you can calculate where the overall centre of gravity will be

    Can you explain this please?
    What is a Shugart (type of) barge?
    Are you proposing a trimaran hull form, using the two 20' x 10' barges joined end on to create a 40' x 10' barge, along with the other two 40' x 10' barges?
    Can the guy in the boatyard give you a rough idea at least as to the weight of these barges? And tell you what their construction material is?
    Can you post some photos of the barges please?
    And please post copies of any sketches / drawings you have done so far.

    Have you heard about (or visited even) the famous Willy T in the BVI's?
    The Legendary Floating Bar and Restaurant | The Willy T | William Thorton http://willy-t.com/
    This is just a 'converted' timber vessel, and it is very popular, so it shows that the concept works.
    And it should be much easier (in some ways) to start off with a purposely designed barge instead, rather than trying to retrofit an existing vessel, assuming that the funding is available for a new construction project of this size.
  8. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    Don’t forget to include the utilities in your estimate.
    Restaurants use tremendous amounts of power and water, and 100 guests will necessitate a large sewage system or a really large holding tank and some way to empty it legally.
  9. brian eiland
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    brian eiland Senior Member

  10. gonzo
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    gonzo Senior Member

    Your first hurdle is legal. Find out if the law allows you to run a bar/restaurant in the proposed area. If it does, then the design will be constrained by those laws. Then you have the logistics of operating the boat. For example, where and how to refuel, unload sewage, water and food supplies, loading/unloading passengers, etc.
  11. Lunaticum
    Joined: Nov 2023
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    Location: India

    Lunaticum New Member

    Buoyancy and stability can be tricky, but you've got the right attitude diving into it. The weight estimate seems solid, but maybe consult with a marine engineer to be sure. I've heard they work wonders on these aquatic projects. And about mimicking that existing bar, it's like Jay Kay's Café in Dublin – they've got that perfect recipe for a cozy place serving breakfast, brunch, and lunch. Speaking of which, if you're ever in Dublin searching for breakfast places near me, you've got to check out Jay Kay's – absolute heaven for morning cravings! Anyway, wishing you the best with your proposal.
    Last edited: Dec 3, 2023

  12. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    There used to be a large floating barge converted to a restaurant and bar in Rye New York. It was a popular hang out for the wealthy locals from White Plains NY, Rye, and vicinity.. The room had a ceiling with netting just below the ceiling surface, maybe a meter below. On occasion, monkeys were released to scramble over the top of the netting. And a good time was had by all......except for the sometime monkey droppings. That is nostalgia stuff. The barge was there in the mid 1950s. ( I think that I am unintentionally dating myself with this bit of recall. )
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