Low displacement coastal cruiser around 40' / 12M

Discussion in 'Powerboats' started by waikikin, Nov 20, 2020.

  1. waikikin
    Joined: Jan 2006
    Posts: 2,365
    Likes: 130, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Hey Bajansailor, thanks, some nice features there, I like the swing up windows though my visual preference is for three. The side door neat and not to large, would satisfy alongside pontoon boarding arrangements. I'm thinking outloud on this, maybe a greater spread on the outboards and a centre walk through- makes steering link & controls a little more complex though some of the sailing cats seem to get by ok... maybe a a corner seat with a lifting frame again similar to some of the outboard powered sailing cats... some of these boats have heaps more power and speed than I'm aiming at as can only use that pace in limited circumstances. All good food for thought:)
    Jeff.
     
  2. waikikin
    Joined: Jan 2006
    Posts: 2,365
    Likes: 130, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Some of my cockpit ideas are based around the common use on Australian waterfront of "construction punts", these are used by waterfront contractors/bridge and wharf crews and oyster farmers as well as riverfront owners as recreational vessels, lots of flat area, shade and very versatile in adding seats, lounges/tables. I'm thinking around the 400 to 450mm freeboard to the cockpit sole plus headroom for the awning /headlining.
    Qualifying the above with a more elegant delivery;)
    Jeff.
    upload_2021-1-24_15-45-34.png
     
    bajansailor likes this.
  3. Zak Waddell
    Joined: Jan 2021
    Posts: 5
    Likes: 5, Points: 3
    Location: Quebec City

    Zak Waddell Junior Member

    Hi Jeff,

    I like the direction you are going in. In November I started looking in to designing and building a coastal cruiser for my family of 5. Something for me to build in the next couple of years but still very early days. I too am interested in a LDL type vessel, around 40ft, 100hp, 12 knot cruise (a little faster) , lots of open internal space, lines reminiscent of yesteryear cruisers. The difference for me is I need to sleep at least 6 and if the boat were trailer-able then the cost of annual ownership would more than half. Here are a few ideas I have come across that may interest you.

    I am sure you know LDL's need to be very light and thin for the design to work. Although I love the concept I am having lots of trouble fighting with the limited beam, narrow bow entry, shallow aft sections and the idea of a comfortable cruiser that is light, thin and round bilge. All that spells for me is a constant 'rollathon' even in sheltered areas. Irens and other designers ensure a very low center of gravity, active stabilizers and Seakeeper gyros to try and stop this. Its really a monohull sailboat with no keel! The reality is dawning on me that an LDL that anyone would want to sleep in might need to be 60ft+. I am not sure if under 40ft will really work. Which begs the question of: Does it really need to be an LDL? Then I saw this:



    This guy has a heavy old wooden boat that he repowered it with a 40hp diesel which does 9 knots at 2000 rpm! Or so he says.

    Outboards. Awesome for shallow draft but outboards are designed to go relatively fast. I don't know if you can get the propeller/gearbox correctly sized for maximum efficiency. So a gas powered outboard on 9 knot boat is probably going to burn 1.5 - 2 x the fuel of a correctly sized inboard diesel with conventional shaft. Just a thought but I know your shallow draft needs an outboard so .... moving on.

    This Matthews 38 from 1946 has a great layout that completely open the Pilot House to the Aft Deck. I love it as it reminds me of a studio apartment with endless options especially for foldable furniture.



    I have lots more ideas but I will leave it to that for now.

    Zak
     
    waikikin likes this.
  4. waikikin
    Joined: Jan 2006
    Posts: 2,365
    Likes: 130, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Just dropping this here ,
    "some aspects" appealing .. Swan Shadow: The debut of Nautor's Swan in the motor yacht market https://www.sail-world.com/news/234515/Debut-of-Nautors-Swan-Shadow

    Zac, thanks for your thoughts there. I've encountered some similar queries around the stability etc. Thinking the beam really needs to be around the 3.6M/12' as a minimum so accommodations are adequate. Some potential for a deepish forefoot, some vertical bilge keels for level grounding seem appealing and a wide and flatish exit/run aft... yes quite "yachtlike in some regards. There's potential for for water ballast also so the displacement can be varied depending on area of operation & conditions met, at some complication...

    Jeff.
     
    bajansailor likes this.
  5. Mantaray123
    Joined: Jan 2021
    Posts: 13
    Likes: 0, Points: 1
    Location: Pa

    Mantaray123 Junior Member

    Aussie
    I went through your pics. You have the best job in the world. I've worked in a small boat shop in mn but it was nasty and a cloud of resin. Working next to the oprah house on the bay in a monstrous shop is awesome. I can't get the carter out of my head and can't figure out why
     
  6. Zak Waddell
    Joined: Jan 2021
    Posts: 5
    Likes: 5, Points: 3
    Location: Quebec City

    Zak Waddell Junior Member

    Here's what I have come up with to date. Still considering a few things. My main beef is the engine placement. As the aft end of the boat is so shallow there is nowhere to put the damn engine where it is not in your way. A couple of small outboards could be appealing in that sense. Then I could open the whole Helm/Salon to the Aft Deck. My compromise for an inboard diesel is below two settees but also through a main bulkhead. I got inspiration from the Rangeboat, Lutje 33, Matthews 38, Southstar 37 and Georgia attached.
    armor-boat-range-boats-39-cruiser-hybrid-fj43162-18457020170548675552666851564548x.jpg d61e2b032288ef61021735af1437cd84.jpg Lutje 33 Photo.jpg projektbild5f3cf32fef314.jpg Salthouse 37.jpg
     

    Attached Files:

    bajansailor likes this.
  7. Mantaray123
    Joined: Jan 2021
    Posts: 13
    Likes: 0, Points: 1
    Location: Pa

    Mantaray123 Junior Member

    That is a nice looking boat. It makes me think of this style inboard cruiser...
    [​IMG]
     
  8. Zak Waddell
    Joined: Jan 2021
    Posts: 5
    Likes: 5, Points: 3
    Location: Quebec City

    Zak Waddell Junior Member

    bajansailor. You living in bim? I am a Trini living in the snow!
     
  9. bajansailor
    Joined: Oct 2007
    Posts: 1,623
    Likes: 488, Points: 83, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Hi Zak - yes, I have been living back in Bim for 20+ years, after living in England for almost 20 years.
    Poor you, re living up in the far north - I heard winters are pretty brutal up there.
    And especially so for a tropical Trini! :)
     
  10. Zak Waddell
    Joined: Jan 2021
    Posts: 5
    Likes: 5, Points: 3
    Location: Quebec City

    Zak Waddell Junior Member

  11. waikikin
    Joined: Jan 2006
    Posts: 2,365
    Likes: 130, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Some neat offerings there, what's in my head at the moment is twin outboards set to each quarter with a lifting frame and box set either side of a decent width walk through transom, when running looks "normal" but when the engines lifted vertically the boxes rise.... these would need adequate slotted ventilation... the fold down boarding platform close to full width to enclose the rear. I haven't scaled this out at present for the harsh realities as yet;)
    Jeff.
     
  12. waikikin
    Joined: Jan 2006
    Posts: 2,365
    Likes: 130, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Hi Manta, yes, it's pretty good, a little to the west of bridge and opera house. Don't worry, I've spent lots of time in dusty itchy sheds, gritty grimy yards as well;)
    Jeff
     
  13. Zak Waddell
    Joined: Jan 2021
    Posts: 5
    Likes: 5, Points: 3
    Location: Quebec City

    Zak Waddell Junior Member

    waikikin likes this.

  14. waikikin
    Joined: Jan 2006
    Posts: 2,365
    Likes: 130, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Hi Zac, apologies for tardy response... been busy at work and haven't touched own computer for a bit..
    Agree on the styling and the interior seems clustered with lots of built in, must be the low beam for trailer at about 10' or so.
    What I do like is this vid where it's really got a bit of skoot on.
    as below:
    Jeff
     

    Attached Files:

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.