Duffie Boatworks 70 Review: New Hull Design for this Custom Sport Fisher

Hull No. 3 raises an already high bar in custom boatbuilding
A Duffie Boatworks 70 sport-fishing boat cruising across the open ocean.
With her striking profile and distinctive lines, Dem Boys is hard to miss. Courtesy Duffie Boatworks / Chris Rabil

Special delivery: Sign up for the free Marlin email newsletter. Subscribe to Marlin magazine for $29 for 1 year and receive 2 bonus digital issues.

Any crew knows that it’s not if it will break but when. It is on this saying that builder Jon Duffie operates. Duffie, a competitive sportboat captain himself, aims to eliminate downtime with some of the highest standards in the industry while still providing generous space and plenty of options. So, when Tommy Hancock—a boatbuilder himself—was ready to build his next custom boat, he went directly to his tournament rival. I caught up with Capt. Reid Bost and the Dem Boys team in Charleston, South Carolina, this past summer to get an inside look at the boat that’s taking the industry by storm. And it’s impressive, to say the least.

Cockpit and Flybridge

Tied up at the local marina in Mount Pleasant, Hull No. 3 was easy to spot among the custom Carolina boats tied up along the long floating dock. Her ­hardtop and sleek hull vents that ­mirror the house profile were hard to miss. As I jumped into the ­cockpit, I noticed how high the covering boards were, hitting me midthigh all around. Duffie believes in a deeper ­cockpit to keep the crew securely in the boat and as much water out of the boat as possible when ­backing around on a fish.

The cockpit and mezzanine of the Duffie Boatworks 70 sport-fishing boat, featuring a Release Marine fighting chair.
The huge cockpit features a Release Marine Trillion Series fighting chair and plenty of seating and storage in the mezzanine. Courtesy Duffie Boatworks / Chris Rabil

A Release Marine Trillion Unlimited fighting chair commands attention. Air-conditioned mezzanine seating, a Spot Zero purified drinking-water fill, a large fish box that doubles as a livewell, and in the step, a large ice box fed by a Dometic Eskimo ice chipper and a huge divided fridge/freezer also stand out. Traditional deck drains are absent from the cockpit; instead, Duffie utilizes a full transom-length French drain system that he tested on his first boat with great success.

On the bridge, a pair of Release Marine chairs sit aft of a large helm oriented to the port side. The helm features three 24-inch Garmin displays with a full suite of Garmin components and a Furuno omnidirectional sonar with a movable control pad. A long bench on the starboard side provides massive storage, and forward of the helm are three bolstered seats with a stowable footrest below, similar to a recliner design.

The view from the helm is nearly unobstructed, and I could easily make out the entire foredeck; when facing backward, the cockpit is easily in sight.

A pair of 42-foot triple- spreader Rupp Tournament hydraulic outriggers ensure a spread worthy of mention, and on the Palm Beach Towers hardtop is a flush-mounted Starlink antenna—the new must-have accessory for boats of all sizes requiring fast and reliable ­internet speeds while at sea.

The interior salon and galley of the Duffie Boatworks 70 sport-fishing boat.
The salon is decked out in tones of grey and charcoal while also highlighting the builder’s woodworking capabilities. Courtesy Duffie Boatworks / Chris Rabil

Salon and Accommodations

The bright and spacious salon layout shows off a large, gray U-shaped sofa on the port side, with a substantial cabinet and wine cooler on the starboard. Also to starboard, and forward, a generous L-shaped dinette provides room for the entire crew. The galley is situated to port and features four slide-out Sub-Zero refrigerator/freezer drawers. A Fisher & Paykel convection cooktop is mounted flush with Cambria’s Signature Series quartz countertop in Swanbridge, a light gray medium with charcoal accents. A large television sits above the dinette, with easy flip-up access to reveal control panels for many of the vessel’s systems.

Moving through the companionway to the staterooms, the Duffie 70 is arranged in a four-stateroom, three-head configuration. The master is oriented to the port side at the bottom of the steps and features a king bed, a makeup station with a stowaway seat, and a large TV mounted at the end of the bed on the wall. Massive storage is available ­throughout, including multiple hanging lockers. The master head is large, with plenty of room to prepare for a night out on the town on your lay day.

Moving farther forward, a full-size washer/dryer sits on the port side, and just above a small step sits a tackle nook with vertical storage for more than a dozen rod-and-reel ­setups. Beneath this step, entry to the fully finished forward bilge—complete with bright LED lighting—provides access to all forward pumps, fittings and machinery, and doubles as a large storage area for overflow provisions, tackle or accessories.

All the way forward you’ll find the VIP quarters with a raised queen bed, a full private head, and ample storage. Mounted flush with the teak cabinetry is a stand-alone Garmin display, allowing the captain to keep an eye on systems and positioning during those overnight trips and to monitor anchor and collision alarms. Two additional bunk rooms are arranged to starboard, with an additional shared head.

The clean white interior of the Duffie Boatworks 70 sport-fishing boat.
The engine room is home to a pair of new Caterpillar C23B engines, producing 2,400 hp each. Courtesy Duffie Boatworks / Chris Rabil

Engine Room and Performance

Climbing down the engine-room hatch, you’ll immediately occupy a small machinery space featuring a Seakeeper 26, the Dometic ice chipper, freezer controls, and the Optimus steering components. All are protected by a soundproof door for quick and easy access while underway. There is also a nice storage area just under the hatch for storing items such as dredges and teasers to keep them off the deck. Through the subdoor sit two Caterpillar C32B powerhouses ­producing 2,400 hp per side, and two 30 kW Phasor generators. The engine room is roomy, bright and exceptionally clean. So clean in fact, I joked that surgery could be performed in there.

Forward are the climate-­control components, Spot Zero Sea Xchange reverse-osmosis ­system and—tucked away neatly in lockers—the water pumps and Duffie’s proprietary closed-loop cooling system.
As Bost put the engines in and out of gear, we passed all of the big-name Lowcountry sportboats that you see ­stacking trophies and big checks at the local tournaments, trading waves and smiles as this new girl was kindly welcomed onto this block. Poking out into Charleston Harbor, we pushed up the ­throttles. All 70 feet of Dem Boys shifted from a ­leisurely glide to a fast jog as we headed offshore.

The Veem props chewed up the dark water as we cruised along at 32 knots, turning 1,850 rpm and burning 166 gallons per hour. With plenty of power left under our feet, we bumped it up to 2,000 rpm and hit speeds of 36.5 knots, burning 191 gph. Slowing down to idle offshore, we took a few moments to work the boat around in circles in both forward and reverse. The CAT’s 4,800 ponies moved this boat with ease, proving that this machine has no ­problem chasing down green fish for a quick tournament release or waiting out a tournament ­winner for the kill.

The clean white interior of the Duffie Boatworks 70 sport-fishing boat.
The engine room is home to a pair of new Caterpillar C23B engines, producing 2,400 hp each. Courtesy Duffie Boatworks / Chris Rabil

While it wasn’t an overly rough day, it was choppy, but in true Duffie boat-­understanding fashion, we didn’t get any water in the cockpit, aside from a slight misting from the exhaust as we backed into the wind. With a storm coming and this author needing to catch a flight home, we dropped the hammers back to the barn. The 70 charged up the harbor hitting speeds of 43.5 knots at 2,350 rpm, ­burning 240 gph.

Dem Boys is only Jon Duffie’s sophomore sport-fisher build, and while she certainly exceeded all of my expectations, he’s set the bar even higher for himself with Hull No. 4 coming in early-to-mid 2024. But based on what I’ve seen so far in these Duffie Boatworks sport-fishing battlewagons, he will undoubtedly hit that one out of the park as well.

Duffie Boatworks 70 Specs

  • LOA: 71’6”
  • Beam: 20’
  • Draft: 5’11”
  • Displ: 125,000 lb.
  • Fuel: 2,600 gal.
  • Water: 405 gal.
  • Power: Caterpillar C32B, 2,400 hp
  • Gear/Ratio: ZF/2.24:1
  • Propellers: Veem, 5-blade
  • Paint: Awlcraft, Cloud White
  • Climate Control: Dometic

Free Email Newsletters

Sign up for free Marlin Group emails to receive expert big-game content along with key tournament updates and to get advanced notice of new expeditions as they’re introduced.