Boatbuilding Blog

January 3, 2011

Dinghy Idea

Filed under: Dinghy — tomlarkin @ 4:54 am

I’ve got a little 8 foot inflatable dinghy that fits in the forepeak. Anyone who’s ever used an inflatable knows the downsides of them – slow to inflate and deflate, and slow to row anywhere. Really awkward to manhandle, especially on a small mothership.  Here’s a way to carry a better better dinghy on the Coot.

This idea is to hook the stern of the dinghy to the transom of the Coot, and lift and flip the dingy upside-down onto the stern of the Coot.

The drawings show a 9-foot hard dinghy -  a Sherpa or Nutshell Pram for instance. There’s enough space for a 10 foot boat, but weight and leverage might become more of an issue while lifting.  The dinghy shouldn’t interfere with the usability much. Under way, the main outdoor space on the Coot is in front of the pilothouse. This area has a great view, and is away from the smoke and noise of the motor. To get to the lazarettes or the motor without removing the dinghy, you could lift the stem 2 or 3 feet and prop it up with a stick.  It makes a nice place to get out of the rain when working on the motor.  The dinghy shouldn’t obstruct the view out the stern too much.

At anchor, the aft space becomes usable just by flipping the dinghy off the back and leaving it attached.  You could even motor a ways in that configuration if you wanted.  In the stored position, the stem piece could drop into a socket with either a lockable pin through the stem or a padlock hasp attachment. Locking the stem down would make the boat absolutely fixed as well as difficult to steal. 

Dinghy Storage

image

Ideal Dinghy

  • Rigid instead of inflatable
  • Long enough to row well and carry a decent load.
  • Move well under oars
  • Optionally able to use sails

Ideal Dinghy Storage

  • Easy to launch and retrieve
  • Low windage and low center of gravity
  • Won’t block the view or mobility around the boat
  • Minimal hardware left on the boat when the dinghy is removed
  • Stored upside-down so it won’t collect water and leaves, and will stay dry

Launching and Retrieving

Launching is really fast:

  • Unlock the stem piece
  • Grab the bow line
  • Lift the boat from the stem until it’s standing vertically on it’s transom
  • Either drop the boat or lower it to the water with the bow line.
  • Cleat the bow line
  • Unlatch the spring latches and lift the dinghy up off the hanging loops and drop it in the water.

Retrieving is just like launching, except you need to bring the stern of the dinghy around to the Coot transom. This might be difficult if it’s windy or rough. Stand on the stern platform to get the needed leverage to start lifting the boat, then walk it forward to set the stem down on the cabin top.

Mounting Hardware

It looks like Weaver Industries has the attachment hardware already made that would work for this application.

These are the parts that mounts to the Coot transom. They’re pretty unobtrusive.

image

These parts mount to a riser on the transom of the dinghy. They would need to be modified to allow for swiveling 180+degrees instead of just 90 degrees.

image

Mounting detail.

image

Right-Side Up Version

You really need to lift it up a lot to get started, and then you need rollers and chocks to store it. It adds a lot more windage and will collect crud.

image

Lifting With Block & Tackle

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2 Comments »

  1. […] bought plans for a 9 1/2 foot Nutshell Pram to use as a dinghy. I wrote about how I wanted to load it onto the boat a few weeks ago. Then I saw an 8 foot Bolger Nymph pram on sale on Craigslist for a reasonable […]

    Pingback by Dinghy Mount Mockup « Boatbuilding Blog — February 9, 2011 @ 2:47 pm

  2. That looks a lot like our composite nutshell dinghy

    Comment by E-Boat — August 14, 2012 @ 9:35 pm


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