Seaforce 575

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Seaforce 575

Following hot on the transom of the release last year of their all new flagship, Discovery 6.5, Hamilton based Fibre Force, builders of the Seaforce brand of trailerable boats have added yet another new model to their growing line up. Traditionally concentrating on the smaller open runabouts and cuddy cabins, the company has in the last few years gone from relative obscurity to become a serious player in the market. While they don’t profess to be leaders in quantity, they certainly make up for it in quality. The Seaforce 575 offers a fresh look at the styling aspects of trailerboats and provides a well-rounded boat that can rightly be called an ‘all rounder’.

The 575 was released at the 2000 Hamilton Boat Show and although the first boat on display was still unfinished, it attracted huge interest and a number of sales were made within the first few days. Buoyed by the interest, the builders knew they had a winner and soon after the show had the first of the finished models ready for delivery.

The criteria for the new boat were simple: a spacious practical cockpit for serious fishing, full sized cabin for overnighting and a hull shape designed to handle reasonably rough water with ease. They were also conscious of the above-water looks and wanted a boat that would be distinctive, yet pleasing to the eye. In the 575 they have certainly achieved what they wanted.

Mike’s Marine Centre, just north of Auckland, provided the test boat complete with a Mariner 140 V6. This was the same boat that the company used in the 2001 Hutchwilco/Propeller Magazine Poker Run with considerable success. They were easily the fastest single rigged production cabin boat in the event and if it hadn’t been for a few navigational errors – due to the GPS being smashed – they would have finished even higher.

Co-skipper Mike Boyce said of the Seaforce 575’s performance in the poker run, “The 575 was awesome in the moderate to rough water and totally predictable no matter where the waves were coming from. We couldn’t see due to the heavy rain but we never let up and were rapt with the times we managed to put in on each stage”.

One Piece

It’s obvious from first glance outside that the 575 has a very large cabin with plenty of headroom. In fact if it wasn’t for the excellent use of graphics, the bullish lines in the foredeck area could detract from the boat’s appeal.

As the boat is built using a one-piece inner liner, the internal bunks are all moulded as one unit. There are 2m berths either side with a large infill to convert the space into a double for overnighting. A head can be easily fitted under the centre squab and for privacy a simple draw curtain is all that’s required. There’s storage under all three squabs as well as wide side trays with comfortable backrests and sitting headroom for 2 to 3 adults. Any water that does come into the cabin quickly finds its way into the self-draining moulded centre section, which is individually drained into the bilge.

While our test boat wasn’t fully fabric lined inside, it is an option.

There are no side decks so all anchoring is done standing in the forward hatch. Like the anchor locker cover, the acrylic hatch is flush fitted to the deckline, leaving no obvious high spots on the foredeck. There is still plenty of space for a small electric capstan.

Open Plan

With no bulkheads there is a good open synergy between the cockpit and cabin, which also gives the 575 a big boat feel inside. The passenger side comes complete with a stainless handrail and provision in the moulding for a glovebox locker, VHF or CD player. The split moulding also allows for all the wiring from the port side mounted electronic equipment to be ducted out of sight across to the helm opposite.

Moulded footrests are all part of the internal liner for both the passenger and driver and there are even a couple of self-draining moulded trays to port. The helm position has been designed to cope with a large fishfinder/plotter/gps combo and there is still plenty of space for the necessary instrumentation. If you prefer to have your electronics bracket-mounted then there is space for that also.

Standard seating consists of two single pedestal-type swivelling seats with clip-on cushions. You then have the option of a combination of back to backs on both sides and a mix of pedestal and back to back. Even with twin back to backs there is still heaps of space in the cockpit for fishing and the benefit of the extra cavernous dry storage is well worth the investment.

Underfloor storage is long enough for wakeboards, waterskis and fishing rods or can be used as a kill tank. Fuel is carried in the rear section and you have the choice of a 120 litre fuel tank or as in the case of the test boat, three 25 litre tote tanks. Mike reckons this is a great idea for those that find it easier to take portable tanks to the gas station, rather than the boat. There are also wide side trays with six individual rod racks as well as a deep recessed area under the portofino stern for whatever else you need to carry aboard. It’s a little low for tote tanks, but deep enough for a separate oil tank – with external filler. The battery, cut-off switch and water/fuel separator are stowed up off the deck in a concealed locker. A drop-in door fills in the walk-through transom, which leads onto the external boarding platform and telescopic Manta boarding ladder.

The transom coaming includes flat sections specifically designed to take rod holders or a base for a barbecue or cutting board. The cockpit sole can either be flow coated as in the test boat, or covered in Nautolex or carpet. It all depends on what sort of finish you require. The appointments in the standard boat are clean and simple, very unpretentious and the options are up to the individual clients.

Quick & Easy

The Seaforce 575 is rated 90 – 150hp. With 90hp, three aboard and a reasonable load of gear, the speedo will indicate around 40mph. A 115hp will nudge that up to the mid 40’s and if you go right near the top end then 60 mph is not beyond possibility. I found the 2.5 litre V6 Mariner 140 provided all the power we needed and on the Eagle GPS ran an impressive 56.5mph @ 5500rpm, with a 19” Laser propeller.

The hull is of deep vee gullwing form, with 24 degrees of deadrise at the transom centreline and a wide downturn double chine, making for good stability at rest. It’s dry in a following sea, with the full bow shape lifting the hull cleanly out of the troughs. For a first-time boatie, there would be little trouble driving hard in the rough water. The hull is predictable and forgiving and easy to drive, regardless of where the swells are coming from.

Catering For All

The 575 fits into the Seaforce line-up between the Discovery 6.5 and the Adventurer 5.0 and yet doesn’t look anything like either of those models. Interestingly, every model in the range has its own individual style and that’s the way the company likes it. I came away from the test feeling that the Seaforce 575 is a boat that would handle just about anything I could toss at it. It’s a boat that could be set up as a serious fishing machine just as easily as a top-of-the-line day cruiser. The more adventurous may add the necessary extras to make it an overnighter, but let’s not forget it’s still only a 5.75m boat.

As for the power, the Mariner 140 is impressive and proves there’s no substitute for litres. The acceleration and mid-range performance was excellent and as the team from Mike’s Marine proved in the Poker Run, it also delivers the punch.

The Seaforce 575 has the credentials to cater for just about all boating aspects and it has the finish to match. In it size and category as an all-rounder it could take a long time to find something any better than the Seaforce 575.


  • Model: Seaforce 575           
  • Price As Tested : $39995
  • Price (Hull Only)  : $20,250
  • Designer: Seaforce Design Team
  • Material: GRP
  • Type: Cabin
  • LOA: 5.9m
  • Beam: 2.30m
  • Deadrise: 24 degrees at transom centreline Hull Configuration               deep vee gullwing
  • Trailerable Weight : 1250 kgs (est)
  • Engine Capacity  :  90 – 150 hp
  • Power Options   : outboard only
  • Fuel Capacity: 120 litres


  • 700 rpm             @  3.0 mph
  • 1000 rpm          @  5.0 mph
  • 1500 rpm          @  7.0 mph
  • 2000 rpm          @  10.0 mph
  • 2500 rpm          @  17.5 mph
  • 3000 rpm          @  25.5 mph
  • 3500 rpm          @  33.5 mph
  • 4000 rpm          @  38.0 mph
  • 4500 rpm          @  43.0 mph
  • 5000 rpm          @  47.5 mph
  • 5500 rpm          @  56.5 mph

Speeds are recorded on an Eagle GPS and rounded off to the nearest 1/2mph.

Notable Standard Equipment

Five year hull warranty, CPC rated, stainless rod holders,

Notable Options on Test Boat

Back to back seating (port), capstan, road cover, canopy.


  • Make: Mariner
  • HP : 140
  • Model:  2 stroke
  • Cylinder Type : V6
  • Displacement: 2.5 litre
  • Max RPM : 5500 rpm
  • Propeller: 19” Laser 2
  • Retail Price: $16069


  • Make: Hoskings
  • Braked : No
  • Suspension: springs
  • Rollers: Multi roller
  • Std Features: sub lights, wind-up jockey wheel.
  • Price: $3750

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