Ocean Craft Marine The Ocean Craft Marine 11.5m (37’9″) RIB with a redesigned running surface, shock-dampening seats, and an adjustable outboard bracket, among other alterations, improves responsiveness, softens the ride, and promises reduced injury rates for
operators and crew.
During his military career, Todd Salus piloted U.S. Navy gunboats on more than 300 missions in the North Arabian Sea, the Gulf of Oman, and the Strait of Hormuz. It’s safe to say that his expectations for how an 11.5m (37′ 9″) rigid inflatable boat (RIB) would handle in a tight turn are well informed by hard-won experience.
That was until he drove the Ocean Craft Marine 11.5m Offshore Interceptor with a custom running surface redesigned by Scott Porta, president of Porta Performance Products (New Smyrna Beach, Florida).
“The boat was out-performing our venerable 9.5m [31.2′ ] Law Enforcement RIB in most aspects, including high-speed turning radius, and this was a much larger boat,” said Salus, a cofounder of Ocean Craft Marine. “The boat was much softer on wave reentry, too.”
Keith Hubble, the principal engineer at TMS Group, was also aboard the boat, recording data from seven sensors measuring acceleration, g-forces, and other impacts. TMS is an engineering firm that develops naval power and control systems with a focus on mitigating shock and vibration.
“We could all feel the difference between the stock bottom and the Porta running surface,” said Hubble. “Todd had more confidence and could get back on the throttle more quickly. It felt less likely to want to step out on you.”
Salus, Porta, and Hubble are players in a singular collaboration of boat and equipment manufacturers dubbed Project Perfect Storm that came together around the common goal of improving the ride and performance of high-speed commercial boats like the Ocean Craft 11.5m Offshore Interceptor, especially during military and law enforcement operations. Participating companies include Ocean Craft Marine (OCM), TMS Group, Porta Performance, AkzoNobel, Sharrow Marine, Steele Industries, Ullman Dynamics, FLIR, FARO, Hefring Marine, Livorsi Marine, Military Systems Group, Roam Robotics, and Seakeeper.
Ocean Craft Marine From left, Mario Perez (Roam Robotics), Scott Porta (Porta Performance), and Stone Stitcher (Ocean Craft Marine) fit Stitcher with devices for on-water testing to measure the slamming forces on standing RIB personnel.
“There are several agendas here,” explained Porta. “We want to reduce mental fatigue, physical fatigue, and injury. We’re looking for larger margins of safety for tactical turns and roughwater performance.” Salus added, “We want to increase the margins for mission success for these boat crews.”
After leaving the military, Salus, now 61, ran Zodiac’s Military and Professional Products with a team of 13 former boat operators from multiple branches of the armed services. When Hurricane Katrina struck New Orleans, Salus and his maritime academy rescue instructors responded, rescuing people stranded by the floodwaters.
After he’d left Zodiac, Salus and his firm, OCM, became, among other things, U.S. representatives of ASIS Boats, a manufacturer of high-end RIBs in Dubai, who wanted to make inroads in the U.S. market. This was around 2009.
Salus explained that Ocean Craft Marine’s vision is to compete in the highly competitive RIB market for military, law-enforcement, and commercial operations. Among OCM’s early clients in the U.S. were the Maryland Department of Transportation Authority Marine Police, the Texas Highway Patrol Tactical Marine Unit, and the U.S. Secret Service.
“It’s hard for boat manufacturers to differentiate from each other,” said Salus. “We’re one of the few that build in fiberglass and aluminum. We understand both mediums very well.”
Ocean Craft Marine The reconfigured transom of the OCM Offshore Interceptor is fitted with Porta Bracket–mounted outboards.
The running surface of a stock OCM bottom includes a reverse chine that exhibits solid seakeeping abilities and helps the boat track well in tight turns. The design originally came out of South Africa from Ballistic Marine. Roy Nouhra, the owner of ASIS Boats, adapted and perfected that running surface. “The design inherently creates a lot of friction, and this is why the boat has such holding ability,” said Salus. “But because the boat is so lightweight and overpowered, it achieves high speeds and great overall performance.”
In 2022 ASIS was contracted to build and deliver aluminum RIBs for use in Lebanon by the Defense Threat Reduction Agency, part of the U.S. Department of Defense. DTRA’s goal is to reduce the proliferation of weapons of mass destruction in the developing world, and OCM wound up embedded with the U.S. Army’s 5th Special Forces Group to train the Lebanese Army Marine Commando Regiment in maritime interdiction operations.
Ocean Craft Marine The RIB is intended for high-speed patrol and interdiction, which means safely carrying military personnel with operational weapons placements in multiple locations.
“I was approached by the captain of the Texas Highway Patrol Marine Unit, who wanted an 11m platform for counternarcotics and migrant interdiction operations,” said Salus. “We started with a 9.5m [31′ ] boat, and after he experienced how fast and agile it was, he decided it lent itself to an entirely different approach to his mission.” The patrol placed an order for eight of them.
“I loved the 11.5m design that we had initially designed for Texas, and I decided to build one anyway as a demonstration vessel,” said Salus.
He brought one of his boats to the International Workboat Show in 2022 and met Porta, a former world and national champion in offshore powerboat racing and the developer of the Porta Bracket, a popular high-performance hydraulic outboard motor transom bracket.
“We started having a discussion about his work with his transom bracket and his bottom design for the racing boats,” said Salus. “We saw there was some significant applicability to the professional boat market and decided we should collaborate.”
Impact Reduction
One of Porta’s primary objectives for Project Perfect Storm is reducing the impacts on the operator and crew when the boat is running in less-than-ideal conditions. At the Race World Offshore world championships for offshore powerboat racing last November in Key West, Florida, TMS Group and Porta installed impact sensors on two 29′ (8.8m) Extreme raceboats competing in the Mod-V class. One had a custom Porta bottom, and the other had a traditional straked running surface. These are single-engine boats with sterndrives that make about 650 hp (487.5 kW) and have fully enclosed cockpits. On average, the Porta bottom reduced impacts by 1 g.
Ocean Craft Marine Shock-dampening seats from Ullman Dynamics enhance crew safety, comfort, and readiness in rough conditions.
The data Porta collected about the reduction of the slamming loads and g-forces on the two-man crew further convinced Salus, who suffered spinal damage from his time on the water for the Navy. In his quest to spare others from similar injury Salus had already been working with Dr. Johan Ullman at Ullman Dynamics (see Ullman’s articles “Designing Consoles for Speed,” Professional BoatBuilder No. 141; “Slamming Standards,” PBB No. 149; and “High-Speed Handlebars,” PBB No. 159) and with Shockwave seats in Canada.
“I was fascinated by [the reduced impacts], and our discussions with Scott went further,” Salus said. “That is what inspired the idea for Project Perfect Storm.”
“We sought to get the leaders in the maritime industry to come out of their competitive silos to donate their engineering talents and latest innovations and asked them to do so in a benevolent manner by recognizing this project as an opportunity to create an environment that is much safer for future professional boat operators.”
Readers might wonder why designers at Ocean Craft Marine would be willing to hand over a million dollar boat to Porta and allow him to alter the bottom. He’s not a degreed naval architect but rather a self-taught intuitive designer who has learned through extensive trial and error. As a youngster, Porta hung around hydroplane racers, who taught him how to straighten a boat’s bottom. Over his years in shops and on the racecourses, he learned to make changes to a running surface to improve its performance based on his experience and gut feeling. His story reminds me of Reggie Fountain II from North Carolina, who has a similar pedigree and was very successful in the high-performance boat business. Porta just doesn’t share Fountain’s appetite for bravado and self-promotion.
“I didn’t have the money to buy expensive parts,” said Porta. “I learned to not leave anything on the table. I pursued every instrument of the orchestra that we know as a boat and made gains with labor and testing.”
When he was racing offshore in Papa’s Pilar, a 32′ (9.8m) Doug Wright catamaran powered by twin Mercury Racing 280 ROS two-stroke outboards, Porta had his first opportunity to change a bottom to see if it would work. (For more on Porta’s alterations of the Doug Wright hull, see “Accommodating Higher Power,” Parts 1 and 2, PBB Nos. 191 and 192.)
He and his driver, Mike Fosse, won the national championship in 2015 without ever claiming a checkered flag. The boat consistently earned podium finishes at every race, and it was the heaviest hull in the class.
“I made it turn better than anything else out there. We would run right up to the pin as hard as we could go,” said Porta. He has offered his bottom to only one competitor in each class, and Porta individualizes it for each application.
“I design the bottom around the guy who is going to run it,” Porta explained. “When you get a bottom right, everything else falls into place.”
For Project Perfect Storm, Porta designed the bottom around Salus’s requirements for a stable platform capable of shock mitigation and predictable performance in all sea states and with heavy loads.
Testing
For every phase of testing in Project Perfect Storm, Salus was at the helm while Hubble monitored and gathered data. The boat was fitted with Ullman suspension seating and Skydex impact mitigation decking.
“The way I operate the boat is indicative of the way that professional mariners would run it,” said Salus.
The first phase of testing was to run the boat with the stock triple Mercury Racing V10 400-hp (300-kW) outboards. The data were gathered during test runs in the ocean off Daytona, Florida, comprising high-speed turns in a predetermined pattern used by the military for training and boat evaluation.
After Phase 1, crews pulled the motors and removed all equipment from the boat prior to flipping it over to allow Porta to spend four months putting his new bottom basically over the existing aluminum hull.
“One of the first things I do when I talk about running surfaces is I say strakes are drag,” said Porta. “When you look at the bottom of a boat and you add up the width of the strakes, it’s an extra foot and a half [457mm] of flat surface that increases pounding.”
He also takes a different approach to watching water come off the bottom of the boat. Porta: “Everybody has paid all this attention to the water coming off the transom, but if you watch a boat from the side, you see that thousands of gallons of water get squirted off the side.” The water sliding laterally and squirting out the side, especially with a stepped-bottom design, gets split by the V in the hull and slides up the bottom panel, hitting a directional change coming off the strake. Forcing water to make all those directional alterations creates inefficiencies compared to having it run one direction for the full length of the running surface.
Ocean Craft Marine Keith Hubble is equipped with multiple measuring devices to record the impacts of vertical slamming forces and lateral accelerations.
“Every time you make a directional change, you lose horsepower,” said Porta. “When the water hits the bottom, I want it to go in a straight line until it leaves that surface. I use the lapstrake to get the water off the bottom of the boat without bending the flow.”
After racing Papa’s Pilar, Porta worked his magic on Nick Scafidi’s 32′ Doug Wright–designed Shadow Pirate, which won multiple world and national championships with Porta’s bottom. “What I learned in Super Stock class, we would get up to 113 mph and the boat would get squirrely in the back,” he said. Porta blamed that on the strake design of the catamaran’s sponsons.
“If you think about strakes, they create all kinds of turbulence,” said Porta, and “the strakes are trying to roll the boat out in a turn.”
His redesigned bottom reduced the influence strakes had on the boat’s performance and made it turn better than the other entries in the Super Stock class. He and Scafidi could run the boat with zero trim and run faster and turn at a higher speed. “It’s a 2% gain across the boat with one of my bottoms,” he said. “A 2-mph gain at 100 mph.”
In the case of Project Perfect Storm, the goal wasn’t all-out speed. It was to smooth the ride in the rough and help the boat turn better in all conditions.
While Porta calls the bottom “strakeless,” half-strakes or mini-strakes would be a more accurate description from someone looking at the photo of the white bottom on the gray hull before the boat was finished in Akzo-Nobel Sea Hawk antifouling paint.
Ocean Craft Marine Porta kept the progressive deadrise, ran the strakes a little farther forward, and added radius to the chines.
Porta created his new bottom shape by hand-applying AwlFair compound using hand-made aluminum tools to ensure that the new running surface is straight.
“When I get it upside down, I start making tools and jigs and glue aluminum extrusions in place to be my forms,” Porta said. “I make these tools with whatever shape I need them to be so when I rest them on my aluminum form edges, I get perfect shapes that I can drag down the boat.” The AwlFair comes in 22-lb buckets for the hardener and 44-lb (10-kg and 20-kg) for the resin, and Porta estimated that he used 35 gal (132.5 l) of the compound to get the bottom right.
The OCM boat has a progressive deadrise. Porta created a radius on the bottom of the chines so the water runs off more easily. “I ran those existing strakes farther forward on the boat and created a little more lift up front and put radii in the chines and left a little of the flat chine because it’s a workboat,” said Porta. “I want it to perform well in a turn.”
Ocean Craft Marine To redesign the RIB’s running surface, Scott Porta applied hard fairing compound and handshaped it with abrasives and custom jigs.
The amended design lets the boat come around in a controlled slide, which couldn’t happen if the RIB had a stepped-bottom design. “We get out there and Todd yanked the wheel,” Porta said of the first test run on the new bottom. “He said, ‘Scott, I’ve run over 300 missions in these kinds of boats, and what you’ve done to this boat has made it handle better than anything I’ve run, hands down.’”
Because the bottom reconfiguration took so long, the team couldn’t replicate the exact conditions from Phase 1 to Phase 2 of testing, but sometimes you don’t need sensors and inertial measuring units to know when a bottom works.
“We were launching the boat into the air on several occasions,” said Salus. “I’m anticipating bone-jarring reentry, and I couldn’t believe how soft it was. I could tell from my butt this was great.”
The next step was to remove the engines and install a Porta Products outboard bracket, which moved the engine 17″ (43.2cm) abaft the transom. For 31 years Porta has made hydraulic brackets that work differently than most outboard brackets, sometimes called jack plates. While they can be raised and lowered hydraulically or manually, the Porta Bracket moves as an adjustable parallelogram, so the attitude of the motor doesn’t change.
“That’s critical because the engines produce their most efficient thrust when the propeller shaft is as close to parallel to the running surface as possible,” said Porta.
Most people think of an outboard bracket being used in a lightweight high-speed application, like a bass boat or racing-style hull such as an Allison, STV, or Mirage tunnel. A bracket can also help an agency or commercial vessel because it can raise the motors to keep the outboard powerheads from submerging when hauling cargo or to let the boat run in shallower water during a military or interdiction exercise without using power trim.
The bracket is made of aircraft-grade aluminum and has four hinges. Each section pivots on polyethylene bearings and is powered by an Oildyne hydraulic pump that generates 5,000 lbs (2,268 kg) of lift per engine. Porta makes multiengine brackets, but each outboard has its own pump. Hydraulic lines have stainless-steel braided winding and connect with stainless-steel fittings.
Ocean Craft Marine The bracket comprises three independent attachment plates and allows for individual adjustment of the three engines’ height and trim.
Unfortunately, when the time came to test the bracket in Phase 3, Mother Nature was in a placid mood: the seas were calm. Hubble couldn’t get the data the team had hoped for on the seven inertial measurement units and one GPS sensor the TMS Group had installed on the boat.
The sensors measured angular velocity, acceleration, roll, pitch, speed, heading over ground, position, and date/time. The main sensor (number 1) was located at the helm. Sensors 2 and 4 were centrally positioned just ahead of the helm, and 3 and 5 were at the bow.
“The closer you get to the bow, the greater the vertical acceleration is going to be,” said Hubble.
Salus explained that there was more benefit from the bracket than Hubble’s data could quantify.
Ocean Craft Marine Porta unloads the custom bracket that will accommodate the triple 400-hp Mercury outboards.
“The part that’s most amazing to me is that we identified the ideal height for the bracket,” said Salus. “We recorded that as the ‘zero position,’ and it didn’t matter if we were in 4′ to 5′ [1.2m to 1.5m] rollers or calm water, if we were at zero, the bracket was set it and forget it.” When trimmed at zero, the motors were tested with and without Mercury’s Active Trim System, and there was no observable benefit to increased trim angle from those zero settings. “We achieved what we wanted with reduced operator input and fatigue,” Salus added.
After the data for Phase 3 were gathered, it was time for the team from Seakeeper to install their custom RIDE antipitch system on the RIB. The system developed for Project Perfect Storm is a one-off that uses more of the actuators than in a typical recreational boat installation (the company didn’t want to divulge additional information about the experimental unit). Seakeeper RIDE technology relies on its own inertia-sensing hardware, custom actuators, and software to control pitch, yaw, and roll. Rotary blades inside the actuators installed on the transom below the water surface automatically deploy to lift the transom and manage the boat’s motion.
Ocean Craft Marine The RIB in its final test configuration reduced personnel’s exposure to vertical accelerations by 27% to 79%.
Conditions for the testing in Phase 4—with moderate winds and chop— were more to the team’s liking, and Hubble recorded some noteworthy data. “We know that we get a 2% to 3% gain in efficiency with the Porta bottom,” said Hubble. With the bottom, the bracket, and the Seakeeper RIDE all working in concert, “we’re seeing in the range of 26% to 77% reduction in vertical acceleration,” he said.
Hubble added, “A 10-g impulse is quite severe. If you can mitigate that down to between 2 and 4 g’s, that’s incredible.”
He recorded corrections of up to 44% in pitch and 31% for roll, which translates into a much more stable ride and a reduction in vertical accelerations.
Ocean Craft Marine Hubble installs sensors at the helm station to measure and record angular velocity, acceleration, roll, pitch, speed, heading, and position.
“When you’re firing a weapon, having a stable platform makes all the difference in the world,” said Hubble. The test indicated that the Seakeeper RIDE helped the boat achieve reductions of 28% in vertical acceleration, 22% in lateral acceleration, and a 25% decline in fore–aft acceleration.
“The user sitting in the seat should experience between 27% and 79% reduction in vertical acceleration compared to if they didn’t have the Porta Bottom, the Ullman seats, and they didn’t have the Seakeeper RIDE working together,” he added.
Porta’s final analysis after the Phase 4 testing: “We have something that’s going to mitigate distraction and fatigue for the operator, and it’s going to let the driver be more focused on getting out of harm’s way or getting out of Dodge. We have a boat that handles better, is more efficient, and causes less mental fatigue to manage.”
About the Author: Eric Colby is the senior editor at Soundings Trade Only and has written about the recreational boating industry for 38 years. He was senior technical editor at Boating magazine and editor-in-chief at Powerboat magazine. A former offshore powerboat racer, he holds the “unofficial” title of fastest journalist on the water, having driven the 36′ (11m) Skater catamaran Flight Club at 172 mph.
