*Twaron® is a high-performance material that offers a range of advantages over fiberglass and steel, particularly in applications that demand a high strength-to-weight ratio, impact resistance, durability, and environmental adaptability. While fiberglass and steel have their place in various industries, Twaron's combination of lightweight, flexible, and high-performance properties make it a standout choice for industries ranging from defense to aerospace, automotive, and marine. Many recognized builders such as Hallberg-Rassy and Nautor Swan incorporate aramid fibers such as Twaron® and Kevlar® in primary impact areas or will lay one or possibly two layers for reinforcement. Bluewater Yachts incorporates Twaron® in alternate layers through the entire hull and deck lay-up schedules.

This is easily the most often asked question and extensively discussed topic onboard at

boat shows. As standard equipment Bluewater Yachts offers the Selden Main Furling

(SMF) in-mast furling system which electronically synchronizes the electric furling motor in the mast with a Selden E40i winch used for the outhaul. Push one button and both

the motor and winch are activated to unfurl the mainsail. Whether Selden or other the

best performance cruising sailboat builders in the world generally supply in-mast furling as standard equipment. The SMF system is the standard for Oyster Yachts, Hallberg-Rassy and Contest. In-mast furling from other manufacturers is also the standard forbuilders such as Amel.

In-mast furling is a simple, completely safe way to manage a mainsail. Pull the sail out

to any size for varying conditions and as the wind builds or falls, adjusting mainsail size

is a simple operation using the outhaul and mast furling motor. When at rest, the sail is

furled completely in the mast so there is no need for covers, of course, and there is no

heavy bulky boom, or large sail cover to contend with. One risk with in-mast furling, the

possibility of jamming the sail in the mast while partially unfurled, is easily mitigated with training. The rare instances of a mainsail getting jammed are based on operator error, in general pulling out the outhaul without releasing/unfurling enough main from within the mast. The SMF system obviates this with synchronized motors.

Rather than furl the mainsail around a rotating mandrel inside the mast using the

outhaul and furling motor control, in-boom furling uses a rotating mandrel, generally

motor driven, but sometimes line driven, inside the boom in concert with the main

halyard. One primary challenge when using this system is making sure the boom is at

the absolute correct angle to the mast so that as the main is lowered, the luff tape rolls

neatly on itself at the forward end of the boom and does not creep forward or aft which

would upset the system. This angle is so critical that most systems employ a boom vang

which does not adjust to set the angle. One benefit to some sailors of in-boom furling is

that if the furling system fails for whatever reason or the mainsail simply has to come

down in a sudden squall for example, all you do is release the halyard and the sail

comes down. That is true, but consider that there is no way to control this main once it’s

on deck and potentially slipping overboard which on the size of boats we build and sail

can be a very dangerous situation.

As with any piece of equipment, learning how to use either furling system well insures

the easiest and safest operation. Practicing in calm conditions prepares you for uncalm

situations when training kicks in and all is done correctly, a key to good seamanship.

If you came to this question for an answer to which system is absolutely better,

unfortunately we can’t answer that for you. Both systems have their pros and cons and

once they are understood a personal decision can be made. We feel strongly, however, that the overall simplest, safest, easiest to use mainsail handling system is the SMF system in particular, in-mast furling in general. What’s great about Bluewater Yachts

however, is that we are a semi-custom builder completely open to and experienced with

all mainsail handling systems, including conventional slab-reefing mainsails on regular

booms and pocket booms with lazy jacks, and on-boom storage systems like the Doyle

StackPack. As with all onboard systems we work with our customers to help choose the

best mainsail handling system for their needs.

Some comments on performance. As racing sailors who have competed at the highest

levels of handicap and one-design racing, and who simply enjoying sailing fast on a

well-trimmed sailboat, we certainly appreciate proper sail shape and design. Upwind in

full-sail conditions, the in-boom furled mainsail will have the best shape and offer the

best performance with a much fuller roach, and horizontal battens. For the same height

mast this main will also have significantly more sail area. What is important to note,

however, is that once the apparent wind starts to move aft, the sail shape advantage

moves toward the in-mast furling main. To work properly the in-boom furling main has a

hard and tight fixed foot without any ability to control the outhaul and adjust draft

accordingly. Also, the boom vang for in-boom systems is not meant to be adjusted as

boom angle is paramount to proper in-boom furling. So as the wind moves aft, the ability to adjust the leech with boom vang angle and the draft with outhaul tension begin to favor in-mast furling’s simplicity.

With sailboat rig design moving toward larger mainsails and self-tacking jibs, the solent

rig has become a popular rig configuration for some builders of performance offshore

cruisers. It is interesting to note that of the hundreds of yachts we’ve been involved with

building and now Bluewater Yachts, all owners were offered their choice of a solent- or

cutter-rigged foretriangle. Of these yachts built to date only one owner, once fully informed, opted for a solent design.

Although convenient for tacking when sailing in moderate conditions, there are two

significant drawbacks to a solent rig. Upwind performance is negatively affected by the

large, light-wind genoa that is furled within inches forward of the self-tacking jib, which

dramatically affects the aerodynamics of the sail plan. In addition to reduced upwind

performance in any winds, in light to moderate conditions the solent rig becomes underpowered, at which point the genoa is unfurled. Now there’s good power although the genoa is negatively affected by the rolled up self-tacking jib at its leading edge. There is also the inherent issue that the genoa will not tack or gybe through the slot between the two sails so it needs to be fully furled for each tack or gybe. Doyle Sails has done a comprehensive study of the solent rig’s performance compared to either a sloop or cutter-rigged sail plan and the results were less than ideal for the solent rig. Hit with heavy weather there are other drawbacks of the solent rig. When winds blow up into the high 20’s, 30’s and higher, a solent jib becomes less effective and less comfortable when reefed as the jib rolls toward the bow. and the heavy clew plate and large block on the clew present a dangerous combination during tacks and if the sheet breaks and the clew gets loose. If this happens it will be difficult at best to get another sheet run to control the sail.

There is a term in sailing called the “center of effort” of your sail plan. You want the

center of effort in general to be nearly over the keel heavier conditions to help the boat

find its way through and over waves as easily as possible. The ability to reduce your sail

plan by reefing your mainsail which moves it’s center of effort forward and switch from a

genoa headsail to the staysail which is set far aft of the bow sets the boats center of

effort in the proper place. Which results in a much more seakindly motion which is better

for the crew and the boat. In truly heavy conditions, a staysail is a game changer.

Noted offshore sailor, sailing educator, and author, John Kretchmer, fully believes in the

cutter rig design. The following is a quote from a Nov 19, 2024, post from Iceland.

“The case for the staysail. Whether we are blasting upwind in a gale, or reaching in the

westerlies, or squeezing out miles in light air, the staysail is a vital part of our sail plan. I

can’t imagine going to sea without it.”

It is important to note as well that the Bluewater 56 was designed as a sloop and owners

often will remove the inner forestay for summer sailing and coastal cruising. The inner

forestay is then put back in place when heading offshore or south during the winter season.

Every Bluewater Yacht is built with an external solid lead keel bolted to its bottom using a parallel-bolt design. Our hulls are also designed with a prominent key in the bottom which fits into a receptacle in the keel for extra resistance to impact damage. Every Oyster, Hylas, Hallberg-Rassy, Discovery, and Contest also uses externally bolted keels, although the hull/keel joints differ. This externally bolted system features two distinct benefits compared to boats built with encapsulated ballast keels.

In general, fiberglass boats with encapsulated ballast keel designs were simply replacing similar wood boat designs. To replicate the keel shape of the wood boats, builders and designers worked together to create molded boats that included the keel shape in the two-part molds. The long keel length and chord width provided ample room to place internal, encapsulated, ballast that was commonly iron, concrete, or lead. The length of these keels combined with an integrated rudder design and propeller aperture offered excellent tracking and protected the propeller. As designers learned more about keel shape and performance and separated the keel from the rudder and then created fin-keel designs, the benefits of encapsulated ballast disappeared.

Molded fiberglass fin-shaped keels that use internal ballast and molded fiberglass fin-shaped keels that have lead ballast bulbs bolted to them have a number of drawbacks and some real safety concerns. In the case of molded fiberglass keel with a lead bulb at the bottom is the fact that the remaining stem of the Keel from the bulb to the Hull is a Fiberglass structure. A solid fiberglass structure is not nearly as strong nor does it have the integrity of a solid lead keel. The energy for a serious impact or grounding could possibly destroy the fiberglass fin leaving the hull breached. Fin keels made from fiberglass fins utilizing internal ballast can also suffer from hard impacts or groundings as the fiberglass layer can crack/shatter and allow water ingress that is very difficult or impossible to stop.

Germán Frers, one of the world’s most renowned yacht designers and the designer of the Bluewater 56 as well as exclusive designer for Hallberg-Rassy and Swan Yachts for decades along with designer for Hylas Yachts over the last three decades is a strong proponent of externally-bolted keels.

I am amazed to learn about non-educated opinions on the subject of externally-bolted versus encapsulated keels on composite yachts. Here are my thoughts regarding the subject.

1. Laminated composite keels are difficult to laminate in a single piece due to lack of space and the difficulty to reach all corners of the mold to do a proper lamination job, which creates a weak point on an important part of a yacht’s structure.

2. The same applies in the case the mold is built in two pieces and needs to be bonded by a lamination over the two halves.

3. Furthermore, the inter-lamination shear at the turn of the bilge it is also an unpredictable weak area.

4. Even a minor grounding touch may create leaks on an encapsulated ballast keel which are difficult or expensive to repair.

5. An external bolted keel attains a better concentration of weight.

6. Bolt condition is easy to check and maintain.

7. Bolt strength is a known quantity.

8. All parts are visible and easy to reach and easier to repair in case of an accident.

9. It is a “state of the art” safe, well considered, and recommended method by expert professionals.

Encapsulated keels are an expensive and un-safe way to save money.