Adventure 40—Deck and Rig Specification

February 2022: This was one of the original articles defining the Adventure 40 concept. We are now in the process of further defining the boat by publishing the detailed specification prepared by the French team, who are going to make the Adventure 40 real. These articles will, over the next few months, supersede this one. In the meantime, we will keep this article available.

Let’s dig into the Adventure 40 deck layout and rig.

But before we dive in to the details, there are a few things I need to clarify:

This is Not Final

To give you an idea of the attention to detail that will go into this boat, I have been very specific in this and the following specification articles. But we will be looking for, and I’m sure finding, better ways to do things, right up until the prototype phase is finished.

For example, the usability and ergonomics of the deck and cockpit layout will be exhaustively tested and optimized. In fact, I’m going to bet that the prototype’s deck will look like it has a case of the pox what with all the filled in holes resulting from moving fittings around—sometimes as little as an inch can make all the difference.

I addition, with things like chain size and type, I have guessed what will be appropriate based on experience, but I have not done any engineering. Rest assured that an engineer will check everything during the design phase and that we will use a safety factor of at least 2:1.

No Options, But Plenty of Customization

In putting together this specification I have kept firmly in mind the Adventure 40 core principle that the boat will come with important items that would be difficult for an owner to build and install, like the arch, while not unnecessarily robbing the owner of the flexibility to customize his or her boat with items that are relatively easy to source and install, like, for example, solar panels to go on the arch.

Don’t Forget The Goal

As you read this specification, please remember that the Adventure 40 is not meant to be the ultimate cruising boat with every piece of cool gear known to man aboard.

Rather, the Adventure 40 will be totally focused on safe, comfortable, and reliable offshore voyaging, at an unprecedentedly low 10-year cost of ownership.

Also, I strongly urge that, as you read this and subsequent specification posts, you don’t let yourself fixate on one or two details that you don’t happen to like. Rather, look at the boat as a whole.

All boats are compromises and no one gets everything they want, particularly not for less that US$250,000.



  • Single bow roller with attachment point for the tack of an asymmetric spinnaker or Code-0 sail, protruding far enough to be sure that the anchor will not hit the bow on retrieval. Engineered to take a downward load equal to the breaking strength of the chain and the upward load of sails set flying.
  • Bow roller to be designed so that the anchor can be stowed securely for all weathers simply be tensioning the rode with the windlass and locking it off with the brake.
  • SPADE anchor of about 55-pounds—one size larger than manufacturer’s recommendation.
  • 200-feet 5/16 G43 high test chain.
  • Chain stopper, strength equal to breaking load of chain.
  • Anchor locker that will stow all 200-feet of chain without hand flaking.
  • Electric windlass with manual backup.

Docking / Mooring

  • Six oversized cleats—most cleats on production boats are way too small—two forward, two aft, and two amidships.
  • If it can be done without compromising the hull to deck joint, cleats to be mounted in gaps in the toe rail (or possibly incorporated into the toe rail) close to the edge of the deck so that fairleads are not required.
  • Two fully enclosed and very strong fairleads about 1/3 forward from the stern at the exact pivot point of the boat under power, to be used for docking springs. Exact placement to be determined by experimentation on the prototype. Fairleads to have clear lead to primary winchs.

Tracks and Blocks

  • All deck fittings by Harken or comparable.
  • All sheet tracks (jib, staysail, main) to have roller bearing cars with tackle adjustment lines such that they can be adjusted under load. Jib track(s) to be long enough and correctly positioned to accommodate all possible jibs from blade jib to high cut reacher.
  • Toe rails to be aluminum extrusions perforated for the attachment of fittings and blocks.
  • All blocks to be roller bearing.
  • Mainsheet traveler on top of hard dodger, clear of cockpit.

Life Lines

  • Pulpit, pushpit, and stanchions at least 30” high.
  • Stanchion bases to be reinforced by toe rail and to be stronger than the force required to bend a stanchion.
  • Life lines to be of high quality 7×19 stainless steel wire nicropressed around thimbles and attached at each end with lashings.
  • No boarding gates.
  • Mast pulpit for security when working at mast.


  • Tiller steering. Tiller to be hinged so that it can be tilted to the vertical to clear the cockpit when not in use.
  • Vane gear self steering. Model not selected. This will be the subject of a lot of testing in the prototype phase.
  • Mounting strong point, cable gland, and power connection for owner fitted tiller pilot.


Two options under consideration:

  • Massively strong semi-balanced—eases steering, both by hand and for vane gear or tiller pilot—spade rudder, mounted in high quality bearings with weaker sacrificial lower half. Rudder removable for inspection or repair without hauling boat (one of the many advantages of tiller steering). I am satisfied that a properly designed and built spade rudder can be made at least as reliable as a skeg hung rudder.
  • Transom hung rudder that will kick up (fused) in the event of a hit from a floating object. A big advantage here is that the whole rudder can be made from composites without the need for a stainless steel shaft—always a potential source of trouble. The problem with this option may be interference with the vane gear.

Lots of design work will be required on the rudder before we come to a final decision.


  • Hard dodger low enough to look over and strong enough to take the loads from a knock down and the mainsheet. Curved lip moulded on aft edge of dodger to ameliorate sharp edge, to be used as hand hold and to drain water away from cockpit. Top surface to be non-skid.
  • Red/white lighting under dodger.
  • Space under dodger to mount owner supplied plotter/radar/AIS, VHF, with cable raceway to switch panel.
  • Cockpit narrow enough that person sitting on one seat can brace their feet on the edge of the opposite seat.
  • Drain so that water does not collect on lee seat when heeled.
  • Large cockpit drains with sea cocks.
  • Good ergonomics to be applied to seat heights, depths and angles to insure comfortable sitting for long hours.
  • Length of cockpit is presently unknown since there are too many design variables, but we will aim for 6-1/2-foot seats for lounging, although this may not be possible.
  • No bridge deck.
  • Entrance to cabin via watertight door with window for light, or if washboards selected, due to ergonomics and space considerations, bottom washboard to be easily and securely locked in position in adverse weather. System must support owner supplied bug screens.
  • Companionway hatch to be capable of being securely latched close, and opened, from on deck or in the cabin.


Substantial anodised aluminum (not painted) arch with following capabilities:

  • Mount for dinghy outboard with lifting rig.
  • Antenna mounting, including radar.
  • Wind generator mounting.
  • Solar panel mounting.
  • Generous cable way to equipment bay below.

All equipment on arch to be owner supplied and installed.

Storm Survival

  • Horizontal chain plates on each transom corner each capable of withstanding a load equal to 75% of the boat’s displacement.
  • Self draining locker with lid capable of stowing appropriately sized Jordan Series Drogue (JSD) with bridle attached to chain plates.
  • JSD itself will not be supplied standard because some owners will not be going off shore, at least at first, and some will want to save the considerable amount of money to be realized by making their own JSD.

To understand the above requirement, please read this series.


  • Secure 6 person life raft storage as close as possible to cockpit, perhaps at aft end between seats.
  • Ten jack line pad eyes: in cockpit inside faces of seats, fore and aft; each side of mast; on deck at forward end of cockpit and at bow. Pad eyes to be sighted such that a crew member can be clipped onto a jack line at all points on deck and able to clip on before leaving the companionway.


  • All cable ways to have messenger lines.
  • All fastenings to be high quality stainless steel and treated with Tefgel or Duralac as appropriate.
  • Vapour proof locker draining overboard sized for two propane tanks (Europe or USA). I hope we can make the tanks 20 pound, but we may have a space problem and need to go smaller.

Hardware Mounting

The hull and deck material for the Adventure 40 has not been selected and won’t be until a builder comes forward, but whatever deck material is used I am committed to mounting all deck gear with fastenings that are threaded into backer plates that are integral to the deck so there are no nuts. This means that any fitting can be removed for re-bedding, working from the deck side only, and such a system will be more efficient in the build. Also reduces the chances of deck leaks.

Chain Plates

I have agonized over these for hours. Stainless steel chain plates in a fiberglass composite boat—the most likely material for the Adventure 40—are just a problem: They always leak eventually, and then they deteriorate.

I’m really hoping we can figure out a way to do the chain plates in some kind of composite at a price we can afford and then bond them into the hull. Or better still, have them as part of the hull. However, such a problem is for an experienced composites engineer, so I’m leaving this issue until we have one on the project.


Mast head sloop with removable staysail stay. I have agonised about making the boat a true cutter with the mast stepped further back and have also thought about fractional rigs. But for simplicity and multi-function capability the masthead sloop is hard to beat.

Enough sail area that overlapping genoas are not required for good performance, but not excessive since in very light air most owners will motor anyway, which is, incidentally, cheaper than beating up your sails tying to keep sailing when it gets light and sloppy. The real keeners can add overlapping genoas, Code 0 type sails and spinnakers, if they wish.


  • Anodized, not painted, aluminum mast and boom.
  • Two spreaders, only slight angle aft, if any.
  • J length spinnaker/whisker pole stowed on front face of mast with alternative chocks on deck for heavy weather stowage.
  • Rigid vang.
  • Antal or Tides type mainsail track system.
  • Separate storm trysail track down to deck so trysail can be stowed on the track in a bag, when not in use.

Standing Rigging

  • High quality stainless steel 1×19 wire.
  • Swages at the top, Sta-Lok fittings at the bottom.
  • Open barrel bronze turnbuckles.
  • Forward and aft lowers.
  • Forestay with Harken roller furling gear.
  • Staysail stay, removable, no roller furling (owner may add).
  • High modulus rope running backstays for use with staysail or storm staysail and to stabilize rig in big seas.
  • Mechanical back stay adjuster.

Running Rigging

  • All halyards and reefing lines to be low stretch and reasonably high modulus rope, although I see no reason to go with the really exotic and expensive options.
  • Sheets to be Dacron.
  • Halyards, one each: jib, staysail, spinnaker (or Code 0), mainsail.
  • Pole topping lift, down haul and after guy (Dacron).
  • Three reefing lines for leach cringles. Simple horn at goose neck for luff cringles.
  • All shackles to be from Wichard, Harken, and Tylaska.
  • Pre-rigged boom preventer system, like ours on Morgan’s Cloud.
  • Simple lazy jack system, like ours on Morgan’s Cloud.


  • LED tri/anchor light. (Purpose-built LED array, not bulb replacement type.)
  • Incandescent steaming light.
  • Incandescent lower navigation lights. Owner may replace bulbs with LED if desired.
  • No deck lighting. Head lamps do a good job for this purpose. Conduit, mast exits, and messenger for owner supplied and installed spreader lights, if desired.


  • All winches to be sized to make trimming reasonably easy for a middle aged couple with bad backs, not race boat gorillas.
  • Five sheet winches in cockpit: two jib, two staysail / runners / roller furling lines (runners and roller furling line(s) to have clutches), mainsheet.
  • Two halyard winches mounted on mast, one each side. All halyards to have clutches.
  • One reefing winch mounted on deck just aft of mast with turning blocks for reefing lines at base of mast and clutches for number one and two reefs.
  • Two winch handles with holders, one at mast, one in cockpit.


This has been a difficult one. Originally I thought that the boat would come with a suit of sails consisting of high cut 100%  jib-topsail (yankee), staysail, and mainsail. But, while that would be great for an offshore circumnavigation, it would not be optimal for inshore sailing or weekending, which a lot of the people who have signed up for the boat are interested in, at least initially.

And then there is the whole issue of light air sails, if any, and storm sails, again, if any. And what about the owner who adds roller furling on the staysail stay? He or she will have different requirements again.

So, after much thought, and in keeping with Adventure 40 core principles (see above), I have decided that the boat will be sold without sails.

However, rest assured that during the prototype phase we will work with a sailmaker(s) to develop and test a full package of sails that will be available directly from them, and that we still have the goal of bringing the boat in under US$200,000 with a basic suit of sails.

Did I Break The Budget?

In looking over this specification, you may wonder, as I have, if I have broken the budget? After all, eight Harken winches, most of them two speed, will cost a pretty penny in themselves.

However, I think we are still going to make our target number of less than US$250,000 ready to sail away, particularly because of the factors explained in this post.

But even if I’m wrong about that, I’m not going to start chopping gear, that I know the boat needs, just to hit a number.

After all, do you want a boat with just two undersized cockpit headsail winches, like many production boats, just to save US$2000? Trust me, after your first offshore passage you will be buying two more winches and installing them anyway. And they will cost you a lot more than the builder would have paid. And what about doing something about undersized primaries? Let’s not go there.


If you have a suggestion to improve this specification, particularly if it is based on first hand experience, please leave a comment, I’m all ears. Please do not go off the topic of this post (rig and deck).

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John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for 25 years, first in yachting magazines and, for the last 20 years, as co-editor/publisher of AAC.

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