Drift Boat Designs

Discussion in 'Boat Design' started by lumberjack_jeff, Oct 31, 2010.

  1. lumberjack_jeff
    Joined: Oct 2010
    Posts: 101
    Likes: 12, Points: 0, Legacy Rep: 99
    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    Our company makes CNC-cut kits to Sam Devlin's designs. (Especially the Pelicano and Grayling)

    We are looking at expanding our catalog. West Satsop Boatworks is named after a branch of the Satsop River in Southwest Washington. As such, it seems like we ought to offer a driftboat.

    I've read (and highly recommend) Roger Fletcher's excellent book on drift boats. The evolution of the modern driftboat is absolutely fascinating. The original river boats were just a basic low-sided, wide-transom, flat bottom skiff with no rocker to speak of. That design limited the fishing opportunities to the lower reaches of the rivers. Area boatbuilders such as Hindman, Kaarhaus and Pruitt gradually put in more rocker and narrower transoms to make the boats useful in the class III and IV rapids in the upper reaches of the McKenzie and Rogue rivers.

    In my humble opinion, they've overshot the mark. Drift boats evolved through stages like the Rapid Robert, which although not especially attractive, were quite useful and versatile. Drift boats have become almost cartoonish; the functional extreme of the basic dory shape. They're designed for 10% of conditions at the expense of the other 90%.

    The way I see it, a modern drift boat has the following limitations.
    • The radical rocker means deep draft. On the shallow but not especially challenging rivers in my area, drift boats don't really "drift" downriver, they bang and clatter over the rocks.
    • The rocker requires radical sheer which requires radical flare of the topsides. To get any meaningful bottom width, a driftboat has so much beam that rowing is difficult.
    • The high stem and transom generally preclude using a motor, and the rocking action will guarantee that the prop either spends a lot of time out of the water, or the powerhead under.
    • It's a one-trick pony. It does that trick (traversing class III rapids) exceptionally well, but many of us don't fish in those rivers. If you want to fish on the lake, or troll the estuaries or go crabbing... you need another boat. (not that I have anything against multiple boats, but in my case SWMBO has another opinion. ;) )

    I'd like to ask your opinions.

    What do you think of this?

    As drawn, it is;

    Length over all : 16' 3"
    Beam over all : 6' 3"
    Design draft : 4"
    Displacement : 802# (at designed waterline)


    The design brief for the West Satsop Drifter is versatility. It is a dory with the capability for an experienced oarsman to navigate class III rapids. The premium is on ruggedness; it can withstand significant rock and log impacts. It will have minimal draft. It can be equipped with a 5 hp outboard and exhibit good open water performance at up to 6 knots in a moderate chop without unnecessary pounding. It will have built-in flotation and feature flexible loading and seating.

    What's different about this design?
    To manage hobby-horsing and enable forgiving loading, about one-third to one-half of the bottom is flat fore-and-aft, similar rocker to the Rapid Robert.
    The bow and transom rise well out of the water to mitigate crashing into rocks.
    The main thwart is longitudinal (it's not really a thwart, then is it?). The Oarsman can position himself wherever conditions dictate.
    It has a shallow v hull. The back half is almost flat, but first three feet or so of the bow has a pronounced V to go through a chop when crabbing or lake fishing. This will also make for reduced slapping during river drifting. (Here fishy, fishy)
    The motor has a splashwell to preclude water coming aboard while running rapids, but the transom notch is an option and can be covered with a snap-on section of canvas for more serious river use.

    I realize that a v-hull (even one with only 4° of deadrise) is unconventional in a driftboat, but I think that the versatility gained make this idea worth a look.
     

    Attached Files:

    1 person likes this.
  2. lumberjack_jeff
    Joined: Oct 2010
    Posts: 101
    Likes: 12, Points: 0, Legacy Rep: 99
    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    What elements of drift boat design can't be compromised?
     
  3. Ike
    Joined: Apr 2006
    Posts: 2,281
    Likes: 204, Points: 63, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    Well, in the first place, drift boats were never intended to be used in open water, in fact most drift boats do not have positive floTation and should never be used in open water. The two uses are opposed to each other. A drift boat does not have flotation because if an accident happens, people go over board, the boat fills with water, the intent is that the boat will fill with water, ground itself and stay put, and not go raging down the river hitting the people who fell out of the boat, and killing them.

    However in open water this is not the case. A boat in open water requires flotation because iif it swamps or capasizes it needs to remain afloat to provide a rescue platform for the occupants.

    So what do you want, a boat for drifting rivers or a boat for open water?

    Actually the first drift boats were dories. They were used by the early explorers and pioneers to drift down western rivers. They picked the dory because they could load a lot of gear into them, they had high freeboard, were stable under heavy loads, and were easy to build with the available wood. Prior to that everyone used canoes or small barges.
     
  4. lumberjack_jeff
    Joined: Oct 2010
    Posts: 101
    Likes: 12, Points: 0, Legacy Rep: 99
    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    Thanks for the feedback.

    I don't mean to sound flippant, but if negative flotation were an inviolable design criteria, wood would be an unsuitable driftboat material.

    I can see the merits of having a capsized driftboat sink (as opposed to floating to the ocean) but I'm having a hard time considering that a safety attribute.

    I fully agree that a boat without built in flotation shouldn't be used on open water.

    I am unconvinced that a boat with built in flotation shouldn't be used on a river. Particularly on the rivers I'm familiar with.

    http://hogislandboatworks.com/coast-guard-certification.html

    http://www.riverstouch.com/OldScow.htm
     
  5. lumberjack_jeff
    Joined: Oct 2010
    Posts: 101
    Likes: 12, Points: 0, Legacy Rep: 99
    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    Here's the real thing at the Wooden Boat Show in Port Townsend

    [​IMG]

    Link
     
    1 person likes this.
  6. FMS
    Joined: Jul 2011
    Posts: 611
    Likes: 22, Points: 18, Legacy Rep: 227
    Location: united states

    FMS Senior Member

    I like it Jeff. Nice work.
     
  7. Hussong

    Hussong Previous Member

    What have you learned about the inclusion of a 4 degree bow deadrise and its ability to eliminate slapping?
     
  8. Ike
    Joined: Apr 2006
    Posts: 2,281
    Likes: 204, Points: 63, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    Yeah, I saw that boat. Nice work.
     
  9. Squidly-Diddly
    Joined: Sep 2007
    Posts: 1,506
    Likes: 66, Points: 48, Legacy Rep: 304
    Location: SF bay

    Squidly-Diddly Senior Member

    Ike, you sure about that "ground itself and stay put"?

    I'm thinking more like get dragged and tumbled along by the rushing water.

    I figure the boat is still fairly light and large and will thus catch a lot of force from the water.

    I've been knocked off a SOT kayak a couple times in classII or III and managed to hop back on at next semi-flat stretch, because my boat and me were floating along together.

    I thought Drift Boats would be at least semi-self bailing like surf boats.
     
  10. Ike
    Joined: Apr 2006
    Posts: 2,281
    Likes: 204, Points: 63, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    Not the ones I've seen that are actually used as drift boats on rivers. Of course I've also seen a lot of drift boats used for purposes for which they were never intended (the same is true of a lot of boats so it's not unique to drift boats). But most drift boat manufacturers apply to the USCG for a Grant Of Exemption from the flotation requirements.
     
  11. lumberjack_jeff
    Joined: Oct 2010
    Posts: 101
    Likes: 12, Points: 0, Legacy Rep: 99
    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    Thanks guys, I'll be able to report more sensibly about her real world performance after a season or two.

    The Coast Guard indicated that Drifter would probably qualify for the exemption, but given her dual purpose as a protected-water utility skiff, I'd like to keep the flotation.

    What's your experience with foam-filled chambers? Feedback I've gotten is that it's a maintenance problem to be avoided, but the CG limits the nameplate HP at 2 without it.
     
  12. river runner
    Joined: Jul 2011
    Posts: 172
    Likes: 6, Points: 0, Legacy Rep: 91
    Location: Colorado

    river runner baker

    To answer several issues brought up. On my drift boat design, I made pedestal seats and a box for the foot braces and filled them all with foam. The way I look at it, if you smash your boat on a rock three days into a week long trip down a river through a canyon, you at least have a chunk of something that floats to get you out.
    My advice for any drift boat designer is to ignore what others have done and just look at how the boat is rowed and what type of river you'll be rowing. I think if you went to New Zealand and found a naval arhitect that has never seen an American drift boat and asked him to design a boat based on how it is used. I doubt very much if it would look like your typical drift boat.
     
  13. portacruise
    Joined: Jun 2009
    Posts: 1,093
    Likes: 28, Points: 48, Legacy Rep: 218
    Location: USA

    portacruise Senior Member

    Sorry if this is OT, but you bring up what many of have experienced in drifting situations.
    I've also been knocked off SOT, and have to walk some thin rapids and negotiate obstacles in my drift.

    There are stable boats designed for drift fishing, like kickboat variations which come in different designs from "V" tubes, to pontoons, and even specialty rafts. Here's one from a world river drifter:

    http://www.waterstrider.com/water-strider-raft-design-details.htm

    Another brand in action on this clip:

    http://www.youtube.com/watch?v=VeEX-EuTSmg&feature=youtu.be

    Sizes from 3 man down to 7# one man on the pontoon type, and no climbing in and out, marinating your feet in muddy water, or launch ramp needed. A SOT is faster if you have a lot of paddling to do, but not as stable nor can it be operated in hands free mode.

    Porta






     
  14. river runner
    Joined: Jul 2011
    Posts: 172
    Likes: 6, Points: 0, Legacy Rep: 91
    Location: Colorado

    river runner baker

    I originally designed my drift boat to be self bailing, but I realized that I didn't allow enough leg room. I would have been almost sitting on the floor. I think self bailing would be a good feature.
    I think you guys are getting a bit off the point. Jeff's company makes wooden kit boats. This isn't a debate about whether a drift boat or a sit on top kayak is the best boat for drift fishing. There are certainly limitations for a drift boat, but there are also limitations for an SOT. Try taking a lawn chair along on your SOT. Or a folding table. Or a seven gallon water jug. Or a BLM required portable toilette. You have to make your own choice about what you need.
     

  15. Hussong

    Hussong Previous Member

    Not to put too fine of an edge on this, cause I pretty much agree with your post... but, the BLM can and will make variances when it comes to what constitutes a portable toilet for self-supported kayak trips on back country rivers. One also does not have to carry all their drinking water if one shows that they have a serviceable, approved filter. Fire pans are also negotiable, but are size limited, so it's wise to make sure your boat can handle the physical shape. A folding table does not have to be of a size for four dudes and a lantern lit card game. There are folding table products on the market for solo adventures that are more than adequate.

    I've done many rivers in the mountain west with a 14.5' Prijon Yukon Expedition kayak and the BLM has never given me grief at any put-in. If a well designed SOT were to have serviceable hatches and lashing systems for the deck, I don't see why one could not go where I have gone. Dude would have to be a real great paddler with that raised center of gravity in Class 3and up, but it could be done.
     
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.