M17 #375 – SWEET PEA

Jerry Montgomery’s Pocket Cruiser Design Changes: Late 1960s through 2016

M17 – 90% of the hull shape designed by Lyle Hess.

Jerry had some set ideas for the type of boat he wanted when contacting Lyle. What ultimately went into production was about 90% Lyle and with the remainder Jerry’s perspective on sailing boat design.

Jerry wasn’t against tinkering with things. There are five keel designs for the M17 where the most common, excluding about 15 or so, are a shoal keel with a centerboard. When the mould for the cast iron centerboard was lost (thrown away by the casting company when they went out of business in the mid-1980s) the keel trunk mould was modified so the M15 centerboard could be used. To make up the needed righting moment more ballast was added to the shoal keel. As a result the ‘M15 boarded’ M17s are not as stiff, because their center of gravity is higher, and have a smaller lateral plane so have slightly more leeway than the cast iron boarded boats.

During the first years of the M17 there are two additional keel setups: a long cast iron fin keel with a bulb at the bottom; and a large swing-keel, much like a Catalina 22, with a crank to raise and lower.

In the mid-70s the flushdeck M17s were developed. All have tall rigs and and the keel/centerboard configuration. It is believed that seven of these boats were built.

There are also a few tall-rig M17s. The rig was designed by Jerry.

In the mid-80s Jerry made a new deck mold changing the cockpit and cabin top.

There were also interior changes: a two quarter berth model with one shorter (port) and the starboard long as on the galley model boats.

In the later-80s Jerry created a new and rare version of the fixed keel boats: a fiberglass fin that is filled with lead. These boats are very stiff, point very high and a quick as they don’t have any turbulence caused by the centerboard slot and a more efficient foil shape. These fixed keel models sail a bit better than the early 1970s cast iron fixed keel version and are less prone to hobby horsing.

M23 – 80% by Lyle Hess

Most notable difference is the difference in how the aft bilges are less full than the M17s as the hull goes from the aft end of the shoal keel to the transom. This makes the boat a bit more slippery in the water. Lyle didn’t like this hull form and he and Jerry compromised on the shape.

Of all the wrinkleboats the M17 and M23 are most alike in hull form

M15 – 100% by Jerry Montgomery

The aft bilges shallows even more than the M23’s and there is no skeg. M15 isn’t a smaller M17, hull shape is very different: bow, sheer, and keel (more efficient foil shape). Jerry says that Lyle really like the M15’s sheer.

The M15’s shoal keel has a more efficient shape than the M17 or M23. The M15’s centerboard section that extends out of the hull is a foil shape v the M17’s & M23’s flat cast iron plate. The house is more rounded than bother versions of the M17 and has more core structure so there is no compression post.

Fun fact – the cover/fill over the porta-potti being an exact fit for the companionway was completely accidental.

Sage 17 – 100% by Jerry Montgomery

Has very similar aft sections to the M15: shallows to the transom and no skeg. The transom is proportionally narrower than the M15’s. The shoal keel is an improvement over the M15’s efficient shape. Bow has a distinctly different: nearing vertical. The curve of the hull from the keel through the bilges up to the hull/deck joint is fuller when compared to the M15 and especially the M23 & M17. The boat experiences less mid-ships pounding as there is less flat surface. The deck is carbon fiber and significantly lighter than the M17s. Like the M15 it has a lot of camber and interior core making it very strong. This means no compression post. The light structure also mean less ballast is needed making for lighter boat weight and less mass above the waterline. The lighter weight resulted in the need for less ballast resulting in less overall boat weight. At the same time the righting moment is greater for the S17 as the center of gravity is lower.

The Sage 17 has the user-friendly potta-potti location of the M15, at the centerline at the aft end of the vberth. Like the M15 the cover also exactly fits the companionway making it quick and easy to store the cover when head is in use and providing privacy.

The Sage 17 has more cockpit storage than the M17.

Sage 17 is much stiffer than the M17 and M15. The center of gravity for the S17 is much lower because of the light carbon fiber deck, light standing rig, and heavy lead filled centerboard.

The overall boat weight is less than the M17 so easier to launch/retrieve and tow.

Vinylester resin v polyester so the hull is stronger/stiffer, lighter and unlikely ever to have osmotic blisters.

The standing rig is lighter than the M17s. This makes it easier to raise/lower and less weight aloft (aka less induced heeling). The headstay connects at 7/8th the mast’s height. The spreaders are swept slightly aft. There is a backstay. The rig is much more flexable than the M17’s meaning a backstay adjuster can be used to much effect (Jerry says, “you can bend the hell out of it!”).

The working headsails are sheeted inside the spreaders to blocks on the cabin top. Larger light wind sails are sheeted outside the shrouds to the toerails. All sheets are controlled by winches on the cabin top: making it simple for the crew, and especially the single hander, to adjust the sail plan (aka much more comfortable and easily done than the adjusting a lee-side sheet on the cockpit combing mounted M17).

All halyards are internal to the mast resulting in less windage (aka heeling) and better airflow across the sail (aka more efficient sailing).

Sage 15 & SageCat – 100% by Jerry Montgomery

Four things: resin infusion, larger cabin, and daggerboard with a bulb

The daggerboard is everything when it comes to how the S15/SC were designed. Jerry spent more time making the daggerboard mould than any other component of the tooling. The foil shape and efficiency of the bulb are exemplary. The S15/SC have the lowest center of gravity of all the Montgomery designed pocket cruisers. On the production S15/SC the bulb is filled with a cast lead pig, not lead shot encapsulated in resin.

Vberth is the longest of all the boats – including the M23 (which is really short for a 23’ boat). Storage under the berth is greater, by a large margin more han both M17 & Sage 17 WITH the flotation foam installed.

The SC mast rotates. The catrigged boat sails closer to the wind than all the other boats and has less leeway.

The fiberglass & structures are made using resin infusion. This results in stronger and lighter components than those for the M15/17/23 and S17. The SageCat and Sage 15 also use less balsa core than the M17/15/23 and S17. This is because resin infusion allows for non-balsa materials that result in a stronger and lighter structure.

More cockpit storage than the M15 and many of the M17s.

The S15/SC are much stiffer boats than the M15. When heeled one gets the feeling that there is a strong righting moment keeping the boat upright and the S15/SC doesn’t heel dramatically in puffy/gusty winds. This stability is also seen, like with the S17, in the boat’s being easily trimmed and holding their own course when using a TillerClutch. The S15/SC feels like a much larger boat when under sail.

I’m often asked what boat do I prefer. Did I enjoy my M15 and M17. An absolute YES. Both boats are excellent sailing craft. The difference being neither sails as well as the Sages. The S17’s sail controls make it just so much better in a wide range of wind speeds. The S17’s cabin is much more comfortable with the large open vberth and more easily used head.

The S15/SC are radically different and superior to the M15. The cabins are more comfortable and have sitting headroom with cabin seats. The two are stiffer than the M15 and when going to weather feel more like sailing S17 because they have a greater righting moment than all the wrinkleboats. The M15 feels different than a M17 … the Sage 15 & SageCat feel more like a Sage 17. The SageCat is such a great sailing boat and so simple – just one sheet to control! Short tacking up a channel or up to a dock in a slipway is easy – like a small dinghy.

Of the five boats which one would I have if money nor storage of the boat were challenges? It is important to note NONE of the Montgomery/Sages are bad boats. Jerry’s boats are the BMW/Lexis luxury sports cars of the pocket cruisers. I really have trouble deciding between a Sage 15 and a SageCat. From a non-sailing perspective they are identical boats (interior, cockpit and rigging time). I really like the flexibility of a sloop sailplan and the ability to hove-to and park the boat (SageCat will do a catboat ‘parking’ maneuver but it isn’t as comfortable nor as easy to do as a sloop’s hove-to). The SC is a better sailing boat than the S15 – as written above points higher and is faster off the wind. Maybe the SageCat if I could only have one.