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Review: Sea Devil 520 | 2022

Review: Sea Devil 520 | 2022

There’s a sacred international formula for driving the Sea Devil boats manufactured by Northern Beaches Marine in New South Wales — drive it like you’ve stolen it, hard, fast, deep, and long. Designed to suit the adrenalin junkie who wants to get to the reef fast or civilised cruisers who enjoy a soft ride, the feisty little forward console 5.2 metre trailer boat offshore missiles offer high performance, incredible rough water handling capabilities, and a simple layout suited to all forms of fishing.  

Now picture this — it’s the back end of the cyclone swell and wind on the Gold Coast and I have one opportunity to test marlin whisperer Richie Inglis’ Simrad electronics package on a boat that I had never seen or heard of locally — his latest Sea Devil 520. With the local weather gods punishing us, Brisbane and Gold Coast conditions are probably the worst I’ve seen in a decade thanks to numerous low-pressure systems producing insane wind, swell, and rain from all directions. It just seems to be the summer norm this year, and opportunities to fish offshore have been few and far between to say the least. So, that one and only test day was set, with light variable winds and a 1.6 metre swell off the Goldy predicted for the day. Considering the fickle weather, that wasn’t too bad, so it was game on for the 15-20 mile trip offshore to chase the summer black marlin off the Gold Coast. 

First Impressions

Rolling in for a dreary-eyed 5am kick off at the Sea World ramp on the Goldy, my first glimpse of the forward console designed Sea Devil 520 took me back to my early days of offshore boating. It’s old-school and commercial-looking but modernised with a combination of sharp and soft lines. Sporting a Suzuki 140 horsepower 4-stroke, a banger Simrad electronics package and a plethora of offshore game fishing tackle and accessories, this boat meant fishy business. 

First up, the solid fibreglass old-school forward console design with deflection lip at around chest height certainly grabs your attention. It’s like a heavy-duty wrap-around screen, and named as a ‘wave breaker’ it’s designed to protect you in rough conditions and help prevent a gob-full when you crack a wave going through the bar. At a glance, these guys have cleverly modernised and disguised the wave breaker with the black external gelcoat, making it look more like a full tinted screen. On that note, full glass screen options are available if the wave breaker doesn’t tickle your fancy.  

Next to catch the eye, the owner has clearly spared no expense at tricking this devil of a boat up with some fancy gear to suit offshore fishing. Externally, he has a custom canopy (with a set of clears for the rough days), the Precision swing out-rigger set, a Suzi 140 horsepower 4-stroke, and Savage c-series dual-axle trailer. A closer look at what’s on offer onboard — well, there actually isn’t a hell of a lot going on when it comes to the layout on the 520. Its one of those ‘less is more’ layouts, and I like it. The 520’s transom setup as standard can either be straight and open with a small port side live-well/storage hatch, and open access to plumbing and cables below. Alternatively, you can have the optional retro-fit oversized live-well as tested. So, if you’re into live-bait fishing, this is a no-brainer option to tick. 

You then have an open and spacious (optioned SeaDek lined) deck through to the forward console, as well as full-length side pockets with toe-locks. The only thing I did notice was lacking — no cockpit kill-tank built into the deck, but I don’t think it’s possible due to the flooding keel feature on these boats. Nonetheless, that’s not a deal-breaker as there’s plenty of deck space onboard for eskies. Up front, you then have the full beam forward console and dash protected by the wave breaker shield, along with under bow open storage for gear. As per the owners requirements, he did not opt for an open bow-hatch to suit anchoring. 

Back to the extra wide protected dash — that allows for large bracket mount electronics, a recessed glovebox, full-length grab-rail above, and separate helm dash at a near-vertical angle for easy viewing and operating of controls. As previously mentioned, this boat is tricked up with one serious Simrad NSS EVO3S electronics package that deserves its own review — see the full specs and details below.

Water Ballast

Before getting into the 520’s dynamite performance and handling, the water ballast system on the Sea Devil 520 is worth a mention. Now, this is something that I've only seen built into aluminium boats from Australia and New Zealand, and always wondered if they could incorporate it into fibreglass boats. Well, clearly they can, as the 520 Sea Devil has a keel water-ballast system added for additional stability at rest. An open flooding section under the transom/floor allows 200 litres of water to settle in the hull at rest, centralising extra keel weight to add a bit more stability onboard. At rest, it floods quickly, and upon accelerating the water drains fast due to the dual bow-breathers allowing airflow through the chamber. The big question is, does it really work and make that much of a difference? Well, I believe it does. The 520 sports a hefty 23-degree deadrise that’s great for chop cutting, however, it can cause any boat to be a tad tender underway and at rest. In this case, I thought the stability at rest to be pretty good considering the size of boat, the deadrise, and toilet conditions encountered on the day. 

Performance and Handling

On to performance — this was the highlight of the day, or more like the year, for me. I could write a novel on this boat’s performance, but I must be as brief as possible. The day starts with launching through the Gold Coast Seaway, calm inside to start, then an instant wake up slap in the face as we exit the seaway. The swell jumped to a mixed bag of slop up to 2 metres, the kind of slop that would normally make you tap off, turn around and go home. Instead, my passenger grabrail grip clamped to a white-knuckle display whilst I hung on for my life, trying to judge the swell, chop, and airborne launches. Captain Marlin at the helm had 20 miles east and a big day chasing marlin in his sights, and most certainly didn’t look like he gave a continental about the conditions. Clearly, he ticked the aerodynamic or flight section of the option box for this boat. No problem, I thought, he’s just showing me how the boat performs in the rough and will tap off to a civilised speed shortly. Not so, as the throttle hand seemed to get heavier as time passed, making me sporadically look back to see if marine parks or the police were chasing us.


After a few quiet prayers and nursing of hand cramps, I started taking note of the rhythm of the ride. It dawned on me that I was in a 5.2 metre boat, tackling 2 metre-plus swell and chop, and without smashing my back to pieces. I’ll give credit to the marlin whisperer — he can drive a boat. Reading the swell and chop, on and off the throttle to suit, whilst loving his 25-knot average speed. However, I’ll also give credit to the hull as this thing slices through the swell and chop like a bread knife through butter. Man, the ride was impressive — soft and acceptably dry considering the conditions.   

At the 15 mile mark the swell jumped to 3-4 metres with variable winds. Again, the ride was incredible for such a small boat. At the end of the day, on the reverse ride with the following sea, that twitchy hand on the throttle had us punching out an average of 27-30 knots. I’d heard Sea Devil drivers are hardcore, and now I completely agree. At one stage, I tried my luck with a comment of, “Ah, tap off to 20 knots please, so I can see what the boat does at standard cruise speeds.” The 520 went from a wild stallion to a calm pony, comfortably easing through the swell and chop, whilst running economically. That only lasted a minute, then it was straight back to wild stallion.

Off the throttle and at rest, the flooding keel/ballast comes into play to assist. 3-4 metre swell and variable gusts certainly added to a few MJ and JT dance moves on deck, however, the slightly tender stability was a small compromise. For me, a soft quick ride is my preference nowadays, and I’ll compromise with less stability if need be.  


On the fishing side, again, it was an interesting day chasing marlin for me. I’m not a huge fan of it, probably because I’m not that good at it. Richie talks the marlin talk, and with 20 grand’s worth of high-end Simrad gear to find these guys, he had us on the money within 15 minutes of arriving. To cut a long story short, the bait is sounded up in 80 metres of water, jigged up, and loaded into the live-well. Success is based on choosing the right spot to drop and the bait activity on the Simrad sonar. When the marlin arch came up amongst the bait on the sonar, it was game on. See the Simrad sonar images below.


So, we drifted, one bait on the downrigger and one in the out-rigger on the surface, with a success rate of three out of five black marlin for the day on the live-baits. On a small boat like the 520 there’s a lot of technical style in chasing these fish when hooked, and when one goes down or you contribute to losing one, just wait for some interesting comments. During the summer black marlin run on the Goldy, the fish are normally between 30-50 kilograms, however, this season saw numerous fish from 50-100 kilograms, and these bigger ones cause all sorts of drama. Nonetheless, it's incredible fishing and some valuable lessons learnt from a marlin guru that I’ll hopefully put to the test next season. 


In a nutshell, the performance and handling on the feisty Sea Devil 520 is insane. You can drive it like you’ve stolen it, or kick back and cruise in a polite fashion — either way, they are impressive. To sum up the layout, there are no frills or bling as standard, but it’s simple, open, and spacious to maximise the fishability. 

As for pricing, Richie’s Devil is tricked up with a high-end Simrad NSS EVO3S electronics package, outriggers, top quality fishing accessories, and a few extra options onboard. Coming in at around $120k in 2020, it’s far from a budget boat, but there’s probably around 40k worth of accessories loaded into this missile. Current standard BMT pricing is from $76k, and that’s not bad at all when comparing to other brands of similar size on the market.

Sea Devil also make a 620 and apparently it sports the same incredible ride characteristics, an open layout and good fishability. I haven’t seen one yet, however, I reckon this could be the ideal long-distance offshore runner of the Sea Devil fleet. This test and the owner’s unique Afroman playlist will most certainly stay embedded in my memory for a long time. 

Weather conditions

Wind: Variable 5-15kt 

Sea: Wild 2-4m cyclone swell    

On the plane

Old school design with a modernised twist.

Ridiculously good high-speed performance and rough water handling.

Forward console design creates larger open cockpit.

Ability to get to spots faster and in more comfort.

Base BMT price is reasonable.

Dragging the chain

No cockpit kill-tank, but plenty of room for eskies on the deck. 

A transom suited to a 150hp’s weight would be nice to see in the future. 


Boat brand and model:  Sea Devil 520     

Price as tested: $120,000 (priced at time of purchase in 2020)             

Options fitted:        

2 x removable seats

Custom centre live bait tank

Dual bilge pumps

LED strip lights

Dual battery setup


Glassed-in B275 transducer

Speaker pods

USB charge point

Deck wash kit

Stainless prop upgrade

Canopy with clears

Full custom boat cover

Rod rack


Trim Tabs

Simrad & JL Audio package, swing outrigger set up, custom bait board.


Type:            Offshore fishing / runabout 

Material:        GRP

Length:        5.2m

Beam:            2.2m

Weight:        Hull only 680kg – towing 1400kg 

Deadrise:        23°


People:  5

Berths:  0

Rec. HP: 140hp

Max. HP: 140hp

Fuel: 140L standard / 180L optional and as tested    


Make/model: Suzuki DF140

Type: In-line 4-cylinder DOHC 16-Valve

Weight: 190kg

Displacement: 2,045cm

Gear ratio: 2.59 : 1 (Two-stage gear reduction)

Propeller: 13 7/8 x 19P


Northern Beaches Marine Pty Ltd


Owner/marlin whisperer — Richie Inglis 

Related articles: 

More Sea Devil reviews.

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