The Dinghy Conundrum Part Two

 78-dink-2

A couple of weeks ago, we invited suggestions for an ultimate rugged cruising dinghy. We appreciate all of you who took time to shoot us your ideas, of which there were many. What you see here and following is our adaptation of some of those, plus a few of our own, into a concept dinghy.

We will start with the engine room. Amongst the Dashew Offshore team there were those that lobbied for a single engine with second trolling engine, and some who favored twins. Single engine proponents argued fuel is always a likely culprit, and that bad fuel would get twins as well as a single engine, so why not pick up a few points in efficiency.

John Henrichs, the master of FPB64-5, Tiger, and a very experienced dinghy hand, had the winning observation. The problem with outboards is rarely fuel, and that is controllable by the operator through modest diligence. Rather, reliability issues usually surface in the cooling system. An impeller goes, or a port becomes blocked. In this case (or any other which causes true loss of an engine), one of two equal sized outboards give you the ability to get home at a good clip.

A pair of  30HP Yamahas are shown, and hopefully we can find two stroke outboards, as they are lighter, less costly, with service techs around the world…

The console and T-top present numerous challenges and trade-offs. The biggest of these is coming alongside an FPB mother ship with our large topside flare angle aft. The arrangement is offset to starboard allowing more clearance to port, on the assumption that the normal docking relationship with the mother ship would be parallel docking on the starboard side of the swim platform.

The T-top and spray shield will provide sun, spray, and some rain protection. If we were operating in the high latitudes we’d wrap a window around the upper portion to reduce wind chill.

We much prefer standing while driving. It gives you a better perspective, and allows your legs to act as shock absorbers.

The T-top framework would be used for lifting the dinghy on deck. A short pennant over the CG could be easily reached from deck level, without having to drop into the dink or fiddle with a boat hook.

The console has room for a chart plotter/depth sounder combo and a bit of camera gear. There is room for three of the 20L fuel tanks under the aft deck, with seating for a couple of guests. The staple rail running across the back of the boat is to assist guests with getting into and out of the dinghy.

It will not be easy to climb out of the water with this dinghy, so we have made allowance for a boarding ladder. This will stow vertically, when ready to deploy. We are going to try to work the details so that when not diving or snorkeling from the dinghy the ladder can be removed and stored somewhere aboard.

You will no doubt have noticed the tent for crew protection if the dinghy should be used as a life raft, and to keep cargo dry.

The idea is to have the port side attached to the gunnel with a bolt rope in an awning track extrusion. When not in use, the awning/tent is rolled up and stored on the gunnel. The extrusion continues around the bow and back down the port side. Into this is a narrow section of bolt rope with fabric, a zipper, and Velcro flap.

To set the tent up should not take more than five minutes, and the flap a few seconds. That is it for NewDink 2.0. We welcome your further input.


Posted by Steve Dashew  (May 13, 2013)




24 Responses to “The Dinghy Conundrum Part Two”

  1. ron Says:

    hi steve,really like the tent and t top nice place for all nav lites and maybe a dry box like used by offshore fishermen for electronics,could store high dollar camera gear and maybe a vhf radio and be sure they don’t get wet.i still like the idea of the transom extensions,but there may not be room for twin eng. to turn, not crazy about the stowable ladder some of us can find a way to fall over board and have no one to hang ladder for us to reboard.maybe a hand grip from top of gunnel to top of motor well on stbd. side and a welded step as low as possible on transom. is that a small solar panel on t top? ron


  2. Steve Dashew Says:

    We will be working in something to aid in getting back aboard without the ladder. So far, we have not been able to figure out a system for transom extensions that does not interfere with getting into or out of the water.


  3. ron Says:

    hi steve didn’t ask in first response but is t bar on aft leg of t top strong enough to take a tow should this be needed, looks like a good place ,fwd of rudder and center line thanks ron


  4. Steve Dashew Says:

    It is designed as a towing post as well as for water skiing.


  5. Bob N Says:

    I think some means of making it extremely difficult to steal the motors is essential.


  6. Matt L Says:

    Steve,

    Metal Shark Boats, the smaller scale Circa Marine of south Louisiana, builds a whole slew of boats in aluminum with optional dive doors. One of the designs is a dive door that opens inward which allows for “boat to boat” transfers. It would really be slick if the port side dive door of the dink was at (nearly) the same level of the swim platform of FPB 97. You could “skip” from the dink to the mothership.

    Seavee is a fairly innovative center console builder in south Florida. Those “Cuban Boys” have a slick hullside dive door that where the steps fold out from a flush deck. So when the dive door is not in use you do not see any evidence of steps. Once the dive door opens you unfold the steps from below the flush deck and you have “insta-stairs”. To preserve the integrity of a “double hull you could create a “coffer dam” like structure under the stairs below the deck like you do for the hull stabilizers on the FPB97.


  7. Steve Dashew Says:

    Thanks Matt, we’ll check this out.


  8. Mike Chaseling Says:

    Hi Steve, can you expand on the 2 vs 4 stroke arguments. My understanding is that 4’s are pretty reliable these days and more common than they used to be? Pete and I are having this debate re #9.


  9. Steve Dashew Says:

    Hi Mike;
    We have been told that the four strokes are indeed more reliable than they used to be. And they run a little cleaner, and do not require oil in their gas. But, they are heavier, more complex, and most of the charter skipper we know prefer the simpler two stroke engines. We have been told they are easier to work on, and service is more readily available. However, our data sample is small. Perhaps Setsail visitors with real world experience on the subject of two versus four stroke outboards would give us their feedback?


  10. Scott Flandeers Says:

    Nearly every dinghy we have owned has been upside down at one time or another. I know it won’t happen to you but it does. A 2 stroke is so simple to get going with no residual issues. Four strokes are different. Simply remove the plugs, remove the carb, shove a fresh water hose in the plug holes and into the engine throat and flush out the salt. Remove the 4 screws on the carb float bowl, clean the jets, reassemble the carb and return it to the engine. Remove and empty the under cowel fuel filter. Pull the engine over to pump the fresh water out of the cylinders. Clean and reinstall the plugs. The engine will start on the 3d or 4th pull but run rough. Remove the plugs, pump out the last bit of water, install new plugs and you be laughin’.

    S.


  11. Shannon Says:

    What about a boarding ladder that lays down in front of the engines,secured by a track, & slides out & down the starboard side? It wouldn’t be ideal but it couldn’t get lost & someone in the water could deploy it.


  12. marcus p Says:

    2 stroke yamahas of 2, 3 and 4 cyl sizes are readily available in New Zealand

    30hp is available in 3 configurations currently. the ‘CV’ or ‘island’ version which is 2cyl and single carb and a rattly beast or the much nicer 3cyl D-series with triple carbs. this one is available with electric start, power trim/tilt and oil-injection


  13. John M Says:

    Steve,
    I think the 2 vs 4 stroke decision would be made based on where you are traveling. Developed countries will be able to service both 2 and 4 strokes. Remote areas tend to have mostly 2 strokes with Yamaha Enduro engines being popular in South America. That being said 4 strokes are very reliable, we have a 90hp Honda that is 13 years old and still runs like a champ.
    I have been following your designs for years, keep up the innovation!

    John


  14. chris Says:

    Instead of hooking the ladder to the stern, chop that corner off at 45 degrees and hook the ladder to that. It will give you more room to climb and not get into the motors, but will flip up out of the way for docking.


  15. Chris Says:

    Little boats are tougher than the big ones….although not a good solution for heavy swimming or diving use, for emergency ladders the Garelick EEZ-In is a pretty slick solution. Slides into a square tube within the hull and is easily deployed with one hand by the person in the water. Just a thought.


  16. Brian Rickard Says:

    After experiencing some awkwardness with a single granny-bar on centreline (difficult to embark/disembark at bow without rocking the boat, and not as convenient for a passenger to hang onto at higher speeds), I am pleased to see that you’ve offset the one in this design.


  17. Daryl L. Says:

    There are pictures of a side entry dive door on this web page. The pictures didn’t copy…

    http://www.leeshoreboats.com/doors-dive-side.html

    Dive Doors and Side Doors
    Consoles
    T-Tops
    Welding Quality

    Home » Customization » Dive Doors and Side Doors
    Dive Doors and Side Doors: with ladder

    Dive Door installed on Jefferson County Sheriff”s Swiftsure 24 Patrol Boat. The dive door has an integral, fold down ladder.


  18. Daryl L. Says:

    I like the offset t top with the lift attachment on it. Maybe add a step on the port side of the console so a short person can easily reach the lift attachment?


  19. Scott Flandeers Says:

    Sorry, I got in on this late. We had our 12′ fiberglass catamaran dinghy at Circa a few years back for them to copy in aluminum with a few modifications like in-hull water traps to stabilize the dink in heavy wind and exit on plane via a large port in the double hull – deck to hull cavity open at the transom. They may still have the measurements.

    A cat dinghy is super stable and super fuel efficient. If you get stuck on a beach by the tide they are easier to slide off vs a mono hull. The boarding stability from the dink to the swim platform is perfect, particularly when carrying groceries or whatever.
    We only used forward chocks (Weaver w/7″ pads) on the boat deck and set the transom on two heavy rubber pads to keep the weight as low as possible. It never moved.

    S.


  20. quoc Says:

    May be some sort of lockable rotating metal bird cage can be designed to prevent theft of those engines. It would be harder for thieves to get at them, so may be they will go look at easier targets.


  21. Daryl Says:

    My friend has a dingy with a poling platform on the back. It gives another level to step up when the docks are high. I have been thinking of a platform that is hinged on a bracket far enough aft that it could be swung aft and down over (or beside?) the engines. My thought is that if the side structure was a rectangular loop with steps hinged down the front it should be able to flip the platform over the back and down to be just awash then the steps swung down from there for steps under the water. That would be a great platform for dealing with scuba gear or getting us older folks out of the water. You might need to go from the inverted platform to the boat outside the main platform loops (most likely on the starboard side for your boat).


  22. Carl E. Says:

    Hi Steve: Not sure this was posted before, but how do you like the saddle-like seating as a compromise between standing and sitting whilst steering a dinghy, as shown for the passenger seating here: http://zodiacmilpro.com/rigid-inflatable-boats/sea-rib-aluminium/ (Please note: at the time of writing, this site takes a few minutes on my PC to load; perhaps weekend maintenance somewhere.)


  23. Steve Dashew Says:

    Howdy Carl:
    We have no experience with the saddle seating. However, we have spent a lot of hours sitting and standing and of the two we both prefer to stand. It gets you out of some of the spray pattern, there is much better visibility, and the legs (bent) help absorb shock. On the dinghy we have aboard Wind Horse there was a light weight consol where the two of us would stand underway.


  24. Carl E. Says:

    If I understand Zodiac’s saddle seat arrangement correctly, it does offer the advantages you cite as well: it offers a seat at a greater height, allowing you the improved view and lessened spray. Like a saddle on a horse (or so I’m led to believe, I subscribe to the both ends and middle-view myself :)), it also offers having your legs bent but supported to absorb shock. It may require to be height-adjustable to really work, though.