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Gunboat G4

2015 July 1

With exquisite lines and a powerful rig, this daysailer is a go-fast beauty


Cruising catamarans were well established before Gunboat. Twin-hulled boats had become mainstream and very popular with charterers. As time went on, the two hulls, connected by a main cabin, expanded to the point that almost the entire rectangle was filled with accommodations. Cruising cats got heavier and heavier. Efficient daggerboards gave way to shoal, very low-aspect, stubby keels. With this evolution the hope of good speed to weather was dramatically reduced. In time the big cruising cat became an accommodation-focused platform that was a far cry from the performance-oriented cats that had initially caught the attention of sailors.

Then came the last America’s Cup and the big foiling cats. I suppose it was inevitable that someone would think of adding foils to a cruising cat. I have said here for many years high performance is always a moving target. With the foiling Cup cats fast upwind speed meant 40 knots. The bar was raised. The Gunboat group set out to design a foiling family cruising cat called the G4. Gunboat’s promotional material says the boat is easily handled.Then Peter Johnstone came along with Gunboat. Peter had a different vision for cruising cats. The first Gunboats focused on performance by combining a fast hull and rig with very nice accommodations but not to the point of sacrificing performance. The idea took off and Gunboat has produced some very fast cruising cats. It’s more accurate to call them cruising-racing cats. 

The prototype G4 underwent successful sea trials in spring and looked to be a very exciting boat. Then, in its first regatta, the G4, capsized in 30 knots of wind. The boat was being sailed by an expert crew and cameras were rolling on the chase boat. All was going swimmingly when all of a sudden a puff hit and the fully powered-up G4 went over. A powerboat righted the G4, and the capsize was analyzed. This event was not considered a catastrophe, rather the growing pains of an unusual, high-performance boat. 


I think that is the right attitude. It’s a huge jump from your mom-and-pop cruising cat to this foiling rocket. Perhaps calling the boat easily handled is a bit optimistic. Perhaps the idea of a family-friendly daysailer was also a bit optimistic, but I think that would depend upon which family you are talking about. To push the G4 to its full potential will require an expert crew fully aware of the specific techniques needed to keep this cat on its feet.

The LOA and DWL are the same, and the average of the light and maximum displacements is 5,940 pounds, giving a D/L of 42.05. With the boards retracted the draft is 1 foot 6 inches. With boards down the draft is 8 feet. The boards are L-shaped, hooking inboard at about a 90-degree angle. T-foils are mounted on the deep rudder tips. The hulls have wave-piercing bows and almost a chine aft and are purely designed for high speed. The beam is 22 feet 3 inches.

The accommodations are as you might expect on this radical boat—spartan. The saloon headroom is 4 feet 11 inches. There are settees port and starboard with double berths outboard. The head is in the port hull with sitting headroom. You cannot access the areas in the hulls from the saloon. There is a dining table in the main cabin.

The rig is huge. The SA/D is 70.82, which is, I think, the highest I have ever calculated for these reviews. But you need a lot of power for foiling boat speed. The asymmetrical chute is 1,250 square feet. I asked Peter if the G4 was a family-friendly cruiser. He said, with refreshing honesty, “Not yet.” But he assured me that the changes were in the works—including hydraulic lifting of the L boards—to make it so.

LOA 39’10”; LWL 39’10”; Beam 22’3”; Draft 1’10” (boards up), 8’ (boards down); Displ. 5,950 lbs.; Sail area 1,378 sq. ft.; Auxiliary Oceanvolt electric saildrive (retractable); Fuel 48-volt, 100-amp-hour lithium ion batteries; Water 11 gal.


829 Harbor Rd. 

Wanchese NC 27981