Cherubini Classic 20

Cherubini Classic 202017-01-02T12:38:36+00:00

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LOA 20’-0”, B 6-10”, D 12”, DISPL 2,050 Lbs., Power 175 to 240 HP

Concurrent with the Moloka’i Strait Motoryachts, Independence Cherubini Company (ICC) hired me to design a 20’ speedboat that would look like the classic speedboats of the early 20th century, but be built in fiberglass with a faux wood finish molded in. Other people were trying to do this, but the artistic effect of the faux wood looked cheap and artificial. ICC felt they could do it better. Mercury Marine at the time was also marketing a jet drive that was basically an outboard motor powerhead mounted atop a jet pump. It was a really neat, compact unit. I used design features from Chris Craft, Hacker Craft, and Gar Wood to create the ICC 20.

The faux wood pattern was an image of real wood printed on fine polyester gauze fabric. ICC made up full-scale flat deck and hull patterns, and scanned those into a computer using a really large scanner. They drew joint lines and bung holes after the fact onto the computer image. A printer then printed the pattern onto the fabric. The fabric was laid down in the boat mold into clear wet gelcoat, and then backed up with light fiberglass chop. After this skin cured, the rest of the solid fiberglass layup was done. When demolded, the pattern looked like real wood under a deep varnish finish, and it was extremely difficult to tell the difference between our faux wood boat and the real thing. We fooled a lot of skilled marine carpenters at the boat shows.

The CC20-02first version of the design was a single cockpit boat with the jet pump behind and next to the transom. The long nose was reminiscent of the racing powerboats of the early boat racing era, but very impractical for family boating because there aren’t enough seats. But boy, did it look sexy (in the male sense of the word). The long nose had enough space to mount a big diesel engine forward of the cockpit with a different jet behind in case anyone did not want the gasoline jet. We never built one of those.

Before the design work was complete on the first boat, we embarked on a two-cockpit version with five seats and an option to carry a gasoline or diesel inboard/outboard drive. That 2-cockpit-I/O drive boat became the production model. Interestingly, the jet powered version got a mixed response: half the viewers at boat shows loved the concept of the jet that would allow the boat to run in shallow water and not disturb the marine bottom too much. The other half would not accept anything other than the rumble of a proper marine engine driving a traditional underslung propeller.

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The boat ran like a champ—we hit a big home run with this design with regards to performance. It was fast, it handled beautifully no matter how it was loaded, and was (is) a sweet running boat. I believe the reason for this is the shape of the boat’s bottom. The performance of all power boats, no matter what type, is governed by their bottom shape—it is the single most important factor in power boat design. In a profile view of my hull design, the keel line is a continuous curve from the stem all the way back to the transom—there is not a straight segment in it anywhere. Yet the deadrise from the mid-body back to the transom is a constant 20°. This is different than most production powerboats which have straight keel lines from about mid-body back to the transom. Straight-keel boats can really run well at only one trim angle and only with one perfect load distribution. At any other loading, they start being cranky to maneuver. My curved keel shape with its constant 20° deadrise, in my opinion, is very forgiving and can run at a wider range of trims than a boat with a straight keel. I have used this basic bottom shape in all my speedboat designs, and they all run really well.

Not all was rosy, however. We soon discovered that the printed wood image was fading very quickly in sunlight. It turned out that the red pigment in the ink was disintegrating under ultraviolet light. At least that was what we surmised. Before we could test that theory and seek an alternative ink, however, ICC went out of business and production of the ICC 20 stopped.

Finally, David Cherubini, another family member, came to resurrect the business as Cherubini Yacht Company, and he acquired the molds for the ICC 20, calling it the Cherubini Classic 20. And instead of the faux wood under the clear gelcoat, he builds the boats with real wood for the decks, overlayed onto the fiberglass deck structure, and for interior panels and trim. Less expensive versions are available without the wood decks if you like.

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The technology of printed faux wood patterns for fiberglass boatbuilding has improved, and I guess the fading problems may have been solved. However, we also found that if that fabric slipped in any way during its setting into the wet gelcoat, any of the feature lines or details could easily get distorted, and there was no way to adjust the fabric once it’s in the mold—handling; it tears it apart, and then you have a real mess and an expensive lost part on your hands. The talent required to get perfect hulls and decks negated quick and economical boatbuilding. It may be fine for small parts which are easier to mold, but for something as big as a boat, it does not make much economic sense as failures are too risky and too costly.

CC24-01Cherubini also stretched the 20’ design to 24’ and they built another nice boat. I did not have anything to do with the increase in the design shape. And they pointed out to me some of the subtle anomalies in the hull shape—there is not a straight section in the boat where an insert can be made to make the boat longer, especially at the transom where it is usual to lengthen a boat design. But Cherubini managed a respectable build splicing new fiberglass into the middle of the hull, and that boat ran very well too. Visually, it looks very sweet. It’s an expensive build however, and I don’t think they have built a second one.

Overall, the Cherubini Classic 20 was my first significant powerboat design, and it became the master model for my later powerboat designs and consulting.