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Osprey 18 Flats Skiff
Design #: SMD-047

Draft (Keel):
Fuel Capacity:
Freeboard (Fwd):
Freeboard (Aft):
17'-7 3/4"
1,300 Lbs.
6-12 Gals.
6 Degrees

18 1/2"
13 1/2"
40hp Outboard
Wood/Epoxy Composite
4 Persons or 645 lbs.

Since designing the Osprey 18 Flats Skiff back in 2008, it has gone through a number of revisions. One of these revisions was to allow the boat to be built with plywood frames that could be cut out by a CNC router. I recently was contacted by a customer who wanted the plywood frame version, but didn't want to buy the kit. I had been asked about this before, but was always reluctant to do it. For some reason, this time I said yes and went about changing the drawings to make it work. Well, by the time I was done updating and revising I found myself with half a dozen versions of the same boat!
Needless to say, it has gotten far to complex to manage this many versions. So, I have decided to make the plywood framed version the new standard and I am retiring the original, solid wood framed version. This will eliminate having to assemble the frames and should make it easier to find materials. Although the solid wood framing has many advantages, it is getting increasingly difficult to find good quality wood in the correct widths to build the frames.
Osprey 18' Flats Skiff Profile
The Osprey 18 was designed as a simple skiff that would run well with a Honda 40 hp outboard motor. In order to run well with such a modest engine, the boat had to be very light with an efficient hull shape. The hull is a simple V-bottom with a fine entry and about 6 degrees of deadrise at the transom. To keep hull slap to a minimum, neither the chine flats or the strakes transition through the waterline while the boat is at rest. In fact, if someone wanted to simplify things even more, the strakes and chine flats can be left off completely. To keep her from looking slab sided, I designed in quite a bit of flare up forward that transitions to outward curvature toward the stern. While this looks pretty, it makes the hull quite a bit harder to build. If kept light, I expect the top speed to be near 32 knots.

The deck arrangement is very simple with fore and aft casting platforms and a long narrow cockpit amidships. The cockpit measures 94" long x 39" wide. The side decks are about 14" wide to allow walking from bow to stern without having to step down. There is plenty of room on the casting platforms for both an aft poling platform and a bow platform for sighting tailing and feeding fish. Under the fore and aft platforms there is storage accessed from the cockpit area. Hatches have been added to the foredeck and the stern to ease access to the fuel tank and batteries. A small motorwell allows you to build the Osprey without a jack plate, my personal preference. There is a side console option for those who'd like to build her without the tiller steering. See the PDF files below for the drawing.

Osprey 18 Deck Arrangement
The fuel tank was originally a custom aluminum model mounted under the foredeck. Last year the government decided that marine fuel systems must now capture all the fumes that come out of the vents. Evidently they have cleaned up all the other major sources of pollution, like power plants and the like, leaving only us boaters! What this means is that your old simple fuel system is a thing of the past. Now your tank will have three vent fittings, check valves and a carbon filter like on your car. I figured the best way to meet the new regulations was to follow the design philosophy of the Crystal 16 and use a portable tank mounted back aft. This meant that the batteries had to all move forward to keep the boat balanced. Frankly, I like this layout better as it will be cheaper and easier to build while eliminating a long fuel hose. As this is a very small boat, any changes to the location of weights makes a large impact on not only the trim of the boat, but also on its performance. Anyone who builds an Osprey should be sure to check with me prior to moving any weights around!
Osprey 18 Flats Skiff Hull Bottom. 
Due to the curving shape of the Osprey 18, it can't be planked with sheets of plywood. Her planking will consist of two layers of Okoume marine plywood that will be cut into strips (as large as possible) and epoxied on the diagonal to the stringers and frames. Up forward these strips will likely be pretty narrow. Back aft and on much of the bottom, much larger sheets may be able to be used. The bottom stringers are 3/4" x 1 1/2" Douglas Fir or Honduras Mahogany on 6 3/4" centers. Her frames are 24" apart and are cut from 18mm Okoume marine plywood. The transom is 2 layers of 18mm Okoume marine plywood, epoxied together. If you'd like to save some money, you can also use 3/4" AB Douglas Fir marine plywood for the frames and transom. The deck and sole are 12mm Okoume marine plywood. The entire hull and deck will be covered in a layer of 7oz. fiberglass cloth set in epoxy and then painted.
Frame F of the Osprey 18
While her construction is pretty straightforward, it is somewhat complex and will require some skill and patience to do properly. I think a first timer can build the Osprey as long as they take their time and read a lot of boat building books ahead of time. In fact, the first boat is being built by someone with no boat building or woodworking experience! The following is a partial list of the drawings included in the Plan Set:

    Profile & Arrangement
    Hull Lines
    Construction Plan
    Keel/Stem Details
    Machinery Arrangement
    Harpin Detail
    Strake and Chine Details
    Flotation Foam Drawing
    Side Console Drawing
    Hull Frame, Stem and Side Console Patterns (by email in PDF format)

The patterns will be sent to you by email in PDF format. You can then deliver or email them to a local blueprint shop for printing. I can also arrange to have the patterns printed for you for an additional cost. Please contact me for a quote.

A partial list of materials is as follows:

    8-10 sheets of 4mm Okoume marine plywood
    4-5 sheets of 12mm Okoume marine plywood
    5 sheets of 18mm Okoume marine plywood
    27' of 3/4" x 2 1/2" Douglas Fir or Mahogany
    (4) 2 x 6 x 8' Douglas Fir or Mahogany
    70' of 1/2" x 2" Douglas Fir or Mahogany (may need to be laminated in 1/4" layers)
    146' of 3/4" x 1 1/2" Douglas Fir or Mahogany (may need to be laminated from 1/2" thick layers)

This is a very partial list of materials. I will try to add more to it as I get actual amounts used from builders.

Although more "features" could be added to make the Osprey 18 more like the production boats that are available, I'd keep it as simple as possible. It will perform better and be much less expensive to build and maintain.
The Osprey 18 Flats Skiff should make a fine little boat for the serious flats fisherman.

Osprey Photo's
Construction photo of Osprey 18
Dajuane's Osprey
Updated 7/08/14
(Click photo for gallery!)

Image of Luke Walker's Osprey
Luke's Osprey
Updated 7/08/14
(Click photo for gallery!)

CNC Cut Frame Kit:
To simplify construction of the Osprey 18, I also offer the frames and transom parts cut with a CNC router. This saves a lot of detail cutting as each frame is notched for the longitudinal stringers, chines and keel.
If you are interested in buying the Osprey 18 Frame Kit, please contact me and I'll get you a quote including any applicable taxes and the shipping costs.

As printing and mailing study plans is not very profitable for me, I have decided to make study plans available as downloadable PDF files. These can be opened with any PDF reader and most people already have the free Adobe Reader installed.
Please remember that these plans are the property of Smith Marine Design and should not be used for any purpose without my written consent.

Profile Drawing
Profile Drawing W/Side Console
Machinery Arrangement

If you would like to pay by Check or Money Order, please contact me to make arrangements.

Before placing an order, please read the Terms of Sale page. By placing an order, you are agreeing to the terms set forth. This page will open in a new window, so just close the window when you are done. Unless requested otherwise, all international orders will be in metric.

Osprey 18 Stock Plans
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