SONIC 386 STS

Powerboat Magazine / 1997

ARCH-LESS DELUXE

Sonic USA 386 STS is a BIG, fast, tough offshore wave puncher. The only surprise? No reverse radar arch.

Innovation drives the marine industry and entices the consumers who support it. From stepped bottoms to more powerful, fuel-efficient engines, new wrinkles tempt buyers every year. Sometimes, however, when a company builds a new boat, the best thing to do is stay the course and go with what's been successful in the past.

That's exactly the line of thinking Sonic USA and parent company American Marine Industries, Inc. have taken with the 386 STS. The Hollywood, Fla. manufacturer went with what's big, bold and OK--beautiful--when designing its 38'6"-long, 8'6"-wide offering, building a rugged offshore boat that doesn't sell you short on space.

If you've a follower of Sonic USA history, you may notice a distinguishing feature missing on the 386 STS: the reverse radar arch. But going without the arch didn't hurt a thing, because what the manufacturer did include is pure Sonic. With a dry hull weight of 9,000 pounds, the 386 STS has plenty of mass to knock down waves, and below decks there a cabin big enough to house six of your friends.

On the water, the 386 STS proved its worth. Once our test driver saw the coast was clear in the waters off Key West, Fla., last fall, he hammered the throttles to the twin MerCruiser Hi-Performance Series 525 SC powerplants and had the 386 STS flying to a top speed of 76.1 mph.

Sonic USA offers the 386 STS at a base price of $186,500 with MerCruiser 502 Magnum MPI powerplants and no options. The boat we tested had the aforementioned supercharged mills under the hatch and a modicum of options, which boosted the as-tested price to $223,675. You can go even bigger and more expensive with the engines, all the way up to triple-mill packages.

WORKMANSHIP

Over the past 20 years, Sonic designer J. Ross has devised a construction process that makes his hulls among the toughest in the business. His fabrication for the 386 STS boasted unitized construction, as the cabin, deck and hull were fiberglassed together at all the points where they contact with each other. Hull lay-up included 1708 biaxial vinylester resin and Airlite foam filling all the cavities, to create a lightweight, super-strong structure that can handle rough seas.

In addition to being tough as nails, the unitized construction approach gave the cockpit and cabin a smooth, polished appearance. With molded structures, there are fewer seams and the fit and finish on areas such as the bench seat and the cabin structures was unmatched. Protecting all this quality construction was a rubber and plastic rubrail, large enough to keep the boat fee of dings at the dock. Also, a small bolt-on windscreen wrapped around the contours of the boat in a perfect fit.

Sonic didn't skimp on deck hardware. There were six 10" cleats positioned on either side of the boat fore, amidships and aft, so there will be plenty of options when it comes time to tie off. Two bow hatches fit squarely in the center of the deck, while the fills for water and fuel and the waste outlet were all on the starboard side. Arranging the fills on the same side saves time and hassles, a convenience we appreciated. Also, a CMI switchable exhaust system will allow you to go mostly unnoticed, or stand out when crowds are around.

The large engine hatch incorporated the entire bench seat, raising on an Aculift screw jack and three sturdy hinges. The hatch lifted high enough out of the way, allowing good access to the twin motors. Sonic mounted the engines on off-shore racing-style cradles, thru-bolting them to L-angles and then to stringers, with the standard transom assembly. Wires and cables were contained in well-supported conduit, not quite up to raceboat grade, but close. Wiring support and execution was also excellent under the dash.

The smooth yellow gelcoat finish will make the bilge easy to clean. Rex Marine boxes housed batteries on either side of the engine compartment, while a Sea-Fire halon extinguisher and 30-amp battery charger were mounted on the forward bulkhead. All these accessories plus the drive and trim tab pumps were easy to reach.

INTERIOR

Room to move--that's what you'll come to enjoy with the 386 STS. From the wide sunlounge, spacious cockpit and enlarged cabin, rubbing elbows with your friends won't be a concern, unless you want it to be.

The design team at Sonic utilized every bit of space it could find in the cabin, and the ceiling was high enough to allow a 6' tall person to stand up, pretty good for a 38' boat. Stowage space abounded, starting with two huge compartments in the V-berth. While volume was excellent, ease of accessibility was not. Getting to the under-berth compartments entailed wrestling with the one-piece lounge cushion, so if you stow anything here, don't plan on accessing it easily. Most likely, it's a good place for extra life jackets or other things you won't reach for often.

Lounge cushions on both sides of the cabin raised, revealing carpeted stowage compartments separated by bulkheads. These areas were not huge, but you'll appreciate the attention to detail Sonic took to finish them off by smoothing out all the rough edges. A hanging locker was built to starboard, forward of a fully molded head. The facilities included a sink and shower assembly for rinsing off after a dip in briny water. Two spotlights in the head kept the area illuminated, while a cabinet was built into the bulkhead, utilizing the space under the driver's dash.

The Sonic 386 STS's port galley was sparse, but the manufacturer intentionally kept it to a minimum. Our test boat came with a sink that had hot and cold running water, but there was space for a refrigerator, microwave or entertainment center. Another cabinet offered even more stowage capacity. Our only complaint was that the countertops were not fiddled, so items could slide off if things get tippy.

Moving into the cockpit, we found the classic offshore-style setup of two front power bolsters and a bench seat, but this was no ordinary bench seat. It was actually more like three-bucket seats, each having its own headrest. If you think this arrangement isn't the best for relaxing at the dock, you're right. It's not. But when you're bouncing off waves with a full crew on board, everyone is likely to be secure and happy.

Speaking of happy, the driver is certainly going to be delighted, especially when he looks at the sharply configured two-tier dash panel, smartly protected by a Plexiglass screen. Ross designed the helm layout by first mounting a Ritchie compass on the flat part of the dash just behind the windscreen. On the upper tier of the dash, from left to right, was a Teleflex depthsounder, two tachometers and a 100-mph Gaffrig speedo. Just below the main gauges were readouts for water temperature, oil pressure and boost, while all the way to the right were the trim indicators.

The bottom tier featured a fuel gauge, along with the oil temperature and water pressure gauges, and the trim and tab buttons. All the accessory switches were in a single row on the bottom tier and clearly labeled. To the left of the steering wheel we found the indicators for the Sea Fire monitor and Safe-T-Alert vapor detector, while to the right the Zero Effort throttles and shifters were in a good position for our test driver.

The co-pilot's dash had three cupholders built in, along with a deep ice chest that drained overboard. A marine radio also was built into the dash, while on the floor, both driver and co-pilot had fixed two-position footrests.

PERFORMANCE

Sonic boats are built as open-ocean bruisers, and the 386 STS we tested didn't disappoint us in big seas off Key West. Tackling the few 4' swells we could find, our 9,000-pound beast begged for more no matter how hard we pushed it.

An upgrade we appreciated, the 525 SC motors with Bravo One drives spinning Mercury Mirage Plus 14 1/2 x 25 three-blade stainless-steel propellers through a 1.5:1 reduction provided a combined 980 hp and plenty of zip. On the way to a 76.1 mph top-end at 5200 rpm, the boat ran eight mph at 1000 mph, 10 at 1500 and 18 at 2000. We went faster in a hurry, climbing to 28 at 2500, 37 at 3000, 48 at 3500, 55 at 4000, 66 at 4500 and 75 at 5000.

Acceleration was acceptable, considering the heft of the 386 STS. The boat reach 19 mph in five seconds, 25 in 10, 41 in 15 and 67 in 20. Time to reach plane was 5.7 seconds without the tabs, and maintaining a level attitude required at least 18 mph. The 386 STS's deep-V hull had a 25-degree deadrise at the transom, two full-length outside lifting strakes and another pair of inside strakes that terminated 8' from the notched transom. The flat chine measured about 3" wide.

As we mentioned earlier, the faster the 386 STS moved, the better it handled. Slalom turns at 30 mph earned only average scores, but got markedly better at 40 and were downright spirited at 50. During high-speed circles, the boat felt sure-footed and stayed on track. Performance in quartering, head-on and following seas was excellent and we heard nary a rattle when we landed after launching of a big swell. The boat was fitted with trim tabs, but our test driver never had to use them. Hydraulic steering by Marine Machine made driving at all speeds smooth and effortless. From the driver's bolster, visibility over the high deck of the 386 STS was perfect, even when docking.

OVERALL

Sometimes, it's best to stay with what works. From a stable ride to a spacious cockpit and cabin, Sonic USA lets you live it up in a large way. If going big is what you're after, you can't go wrong with the 386 STS.

WORTH NOTING

It doesn't get any closer to unitized construction than Sonic USA. The hull, deck and cabin liner are bonded together to give the boat a strong, solid feel, not to mention a smooth, finished appearance.

Classic deep-V design absolutely crushes quartering, following and head-on seas. If you plan to play hard, this boat is up to it.

Side walkways provide easy foredeck access, a rarity.

STANDARD EQUIPMENT Full instrumentation, compass, molded windscreen, twin bolsters, fire extinguishers, cabin with carpet, galley, complete head compartment, indirect lighting, stereo, stainless hardware, power steering, power engine hatch, race-style engine mounts, K-planes, bilge blowers, automatic bilge pumps.

OPTIONS ON TEST BOAT Upgrade to twin MerCruiser Hi-Performance Series 525 SCs ($25,900) hydraulic steering ($4,700), mufflers ($4,400), power bolsters ($1,300), VHF ratio ($875)

ENGINES Model MerCruiser Hi-Performance Series 525 SC Cylinder type V-8 Cubic inch displacement 454 c.i. Lower unit gear ratio 1.5:1 Max. prop horsepower @ rpm 490 at 5200

PROPELLER Mercury Marine Mirage Plus 14 1/2" x 25" three-blade stainless

POWERBOAT TEST RESULTS

SOUND LEVEL 86 dBA (open)

FUEL CAPACITY 200 gallons

TEST CONDUCTED AT KEY WEST, FLORIDA.