Review: Mac 420 Highside

By: Norman Holtzhausen, Photography by: Norman Holtzhausen

Mac 420 Highside 05 Mac 420 Highside 05
Mac 420 Highside 01 Mac 420 Highside 01
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The Highside version of the Mac 420 is a logical and worthwhile response to customer feedback. Listening to your customers is a good thing and, in this case, the result is well worth it.

The popular Mac 420 model has been one of the mainstays of the Mac boats range, hitting the ‘sweet spot’ as a small, economical runabout that is easily towed and launched yet can, when required, handle rough conditions. The foam-filled pontoons ensure this boat is completely unsinkable, even if cut in half, while the rotomoulded polyethylene is virtually indestructible resisting almost all known solvents and with absolutely no problems of corrosion, UV damage or rotting.

New Zealand, though, is notorious for rough conditions being whipped up with little warning, and the Mac Boats sales team had received feedback its customers wanted something that would be even more comfortable in poor conditions. The relatively low pontoons on the standard 420 can result in a wet ride in significant chop. The call was for something with a higher freeboard, while a few more storage options would also be a bonus.


Mac 420 Highside

Mac 420 Highside

The designers at Mac Boats had previously developed a gunwale extension for the smaller brother of the 420, the 360 dinghy, and this seemed to be the answer. Hence, it has developed a similar add-on module that creates a high-sided version of the existing hull and can be used with all the Mac 420 configurations. Even better, because the module is welded to the existing hull, it can be retrofitted to existing Mac Boats by the factory.

The modification raises the gunwale by 250mm and creates a boat that can handle considerably larger seas than most its size. Although the higher sides do not necessarily affect the safety of the boat (the fully sealed hull was already unsinkable), the ride is drier in a rough sea and provides additional protection from wind and chop.

All Mac Boats have a double-skinned hull, each skin having a thickness of around 10mm. The plastic is almost bulletproof at this thickness and can even withstand a major impact. The boats are built to US Coast Guard, MSA and CE certification standards and therefore comply with regulations virtually throughout the world.


Layout and design

Floor layout of Mac 420 Highside

A range of colours is available and the boat will never need painting as the colour is impregnated right through the plastic. The additional coaming moulding can be made in the same colour as the hull, or in something different to create a stylish two-tone effect. The test boat had the new navy blue hull and the bright white highside, creating a very classy look.

Although the Mac 420 Highside is rated for five adults, the configuration we tested had just two seats, one forward and one aft but on opposing sides of the hull. This gives the helmsman an unimpeded view while balancing the boat both laterally and longitudinally.

The seats are standard plastic units with covered squabs and are both mounted on pods with some storage underneath, while other seating configurations are possible. A stainless steel bowrail provides handholds for the occupant of the bow seat and also allows the fitting of rail-mounted accessories like rodholders.

A couple of small hatches in the bow casting platform hide an anchor locker as well as a fuel tote tank storage space. This is clever, keeping the fuel weight forward to help balance the boat. A stainless steel fairlead is fitted to keep the anchor rode in place over the bow and a cleat inside the bow is used for tying off. The entire deck is covered in non-slip Nautolex which, like the rest of the boat, only requires a simple hose-down to keep clean.

One of the criticisms of some plastic boats is the lack of built-in storage, but the new sides provide a storage pocket that runs the full length of both gunwales. These securely hold the numerous bits and pieces that every boatie seems to require, while also providing a footing for mounting additional accessories. The test boat had four flush-mounted and two stainless steel rail-mounted rodholders fitted, and there is plenty of space for more.

The Mac 420 Highside had no electronics fitted and with the lack of a dashboard area because of the tiller-steer layout there are limited mounting options. However the high sides do provide
the option of fitting a mounting bracket, such as those provided by Tallon Systems, to hold a fishfinder or other units. Similarly a VHF radio could be permanently mounted in that same sidepocket.



One of the striking features about this boat is the width of the cockpit. The external beam of 2.2m in a boat that is only 4.2m long makes it easily the widest 14-foot boat on the market. Even the internal beam width of 1.7m is wider than most non-pontoon boats.

Hanging off the back of the test boat was a brand-new 40hp Tohatsu oil-injected two-stroke engine. This is right in the middle of the recommended power range of 30 to 60hp and provides plenty of grunt. Although more fuel-efficient four-stroke options are available, these come at a cost both in dollars and extra weight and the Tohatsu is a good option for the average user. This motor is electric start, which means it also provides battery power for accessories, while the tiller-steer configuration keeps the cost down.

The powder-coated battery box in the centre of the transom intrudes into the cockpit slightly but is the ideal position for locating a baitboard. A small boarding platform either side of the motor provides a step for swimmers or divers to get back on board. No boarding ladder was fitted but there is space to do so.

Internally the boat is very neat and clean, with the grey Nautolex floor offsetting the blue hull and white sides. Grabhandles have been fitted to the cockpit cabin sides. The welds between the hull and high sides are extremely neat and very solid.


Handling and ride

Mac 420 Highside on the water

It was a calm morning with very little chop when we slipped the Mac 420 Highside off its NZ-built single-axle trailer (with waterproof LED lights) into the water. Although the trailer has skids rather than rollers the boat slipped off easily thanks to the low-friction coefficient of the polyethylene.

Anyone who has ridden in a plastic hull will know the superior impact-absorbing and sound deadening qualities of the material and the 420 showed this to full advantage. Although it was a very calm morning we found a couple of wakes to power through. Despite having a shallow 11-degree deadrise, landing off these was a lot more comfortable than most boats of this size. The conditions did not trouble us but the wide beam means this boat will be stable and comfortable in considerably rougher seas.

This size of boat is not about flat-out speed but the modest 40hp motor nevertheless got us into the high 20kt range easily enough. The powder-coated aluminium transom benefits from the sound dampening of the plastic underneath so there was no engine noise transmitted to the hull. Despite absolutely no protection from wind or spray, we felt comfortable in either of the seats and remained completely dry. Of course in a chop this will not be the case, but it was clear that the high sides are a definite improvement in terms of protection for the occupants compared to the previous model.

Boat handling was good, with turns being tight and controlled. The short waterline length could result in the Mac 420 Highside being thrown about a bit in rougher conditions, but we had no such problems. Of course the pontoons and broad beam mean this boat is supremely stable at rest.

Heading back to the boat ramp we found the high and low-speed handling were both good. A tiller-steer motor is easily the best for quick, close-in manoeuvring and getting into the tight area of the ramp was no problem. The rubbing strip along the outer edges of the hull meant no worries about fenders when coming alongside the wharf and we soon had the boat back on its trailer. With a hull weight (excluding motor) of just 275kg this is a very easy tow with a normal family car.


The Trade-a-Boat verdict

Mac 420 Highside boat

We have previously found the Mac 420 Highside to be a great little boat and this new evolution Highside version makes it even better. A spacious, stable and maintenance-free vessel that is nevertheless easy to handle and tow, again supporting Mac Boats’ philosophy of "Boats for Life". 



• Unsinkability

• Warmth and softness of the plastic surface



• Lack of shelter from the elements


Mac 420 Highside specs

Mac 420 Highside price: $21,995

Price as tested with 40hp Tohatsu two-stroke outboard motor






MATERIAL Rotomoulded polyethylene

TYPE Monohull (five-year hull warranty)


BEAM 2.2m


WEIGHT 275kg (hull)




FUEL 25lt (tote tank)

HP RANGE 30 to 60



MAKE/MODEL Tohatsu M40D2EFTOL outboard motor

TYPE Oil-injected two-stroke outboard motor w/ electric start and trim




Mac Boats

36, Cryers Road,

East Tamaki, 2013, Auckland

Phone 0800 370 007 or 09 273 566




See the full version of this review in Trade-A-Boat #257, September 2015. Why not subscribe today?

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