Pontoon boats, with their innovative chamber design, have always been promoted for their safety, however New Zealand builder Senator Boats has taken their product much further to produce a fantastic offshore fishing vessel. BARRY WISEMAN reports.

They may look cumbersome on the water, but stepping aboard and riding in a Senator aluminium craft soon changes your mind. 

Don’t be fooled by the shape. 

This is not really a pontoon boat, rather a sealed hull below the water and a multi-chambered sealed alloy collar around the gunwale that prevents the boat from sinking in an emergency.

The outer collar, marketed as the Guardian Chamber System, provides positive buoyancy above the waterline. 

To evaluate their unique design, the company loaded up its Senator 620 model, complete with outboard motor and the maximum rating of six people, and with the assistance of Coastguard NZ conducted a flood test in Auckland Harbour. 

With the rescue authorities alongside, Coastguard personnel pumped seawater into the vessel until it was submerged. 

The water level reached its sealed multi-chambered collar, still with the six people sitting or standing inside the cockpit, with the rescue authorities standing by. 
The vessel remained afloat.

A great testament of the design and safety features which goes into all the Senator range, from the 400 to the 860 models.    
 
In this review we are looking at the new Senator 500CU, which took out the Boat of the Year award at the Auckland Boat Show. 

That same chambered collar that keeps the boat stable on the water also helps prevent listing as you put your weight on the gunwale to step aboard. 

Once underway, the sharp entry slices through the waves to soon have the vessel on the plane.

Fresh out of the factory for 2025, the Senator 500CU (cuddy) has an overall length of 5.2m from bow to the end of the duck boards aft. 

The actual boat length on the trailer is 6.7m, taking in the bow sprit and motor.

For a 5m vessel, it’s external beam of 2m makes it a roomy boat to cater for fishing, diving, craypot pulling and crabbing. 

The internal deck space covers 2.2 square metres.

The local agent for Senator Boats is Sportsmarine Boat Centre at Bunbury and the review vessel was ordered with a few factory options to suit our local conditions.

Located at Napier in the North Island of NZ, the designers at Senator Boats present their latest range as a modular system, meaning you can build the boat up from a basic hull to top of the range over time as your budget allows.

Being its first 500CU, Sportsmarine dealer principal Greg Collett decided to opt for centre, long port-side and short starboard bunks in the cuddy cab: the idea being it’s a good place for youngsters to rest up, if need be, during a day trip. Good for storage too.

Instead of underdeck storage space, he opted for a 90-litre fuel tank below deck which helps add to the stability of the vessel at rest or when drift fishing. 

The heavy-duty targa folds down to aid storage at home and a rigid soft-top bimini has been fitted, along with removable clears to prevent the spray coming in on the instruments. 

The package also includes fitting Yamaha’s F75 hp four-stroke engine and a Garmin 10-inch GPS/Sounder combo on the big dash. 

Because this hull has a proven offshore record, the safety pack includes EPIRB, offshore flares, four lifejackets and anchor kit. 

The rig comes on a single-axle Dunbier galvanised trailer.

This new Senator 500 Cuddy cabin model was in Sportsmarine’s Bunbury showroom for only a brief time before it was snapped up by the new owner. 

He opted for a couple of extras such as dual batteries, electric anchor winch, and sound system.

“One of the major attractions of this vessel is the size and its offshore capabilities,” skipper Dale Humbley said as he prepared to launch the craft.

“It’s a very capable boat, plus easy to manage on the water and back home when manoeuvring for storage. 

“Construction is very solid and with two-plus square metres of interior deck space, it has the room for various forms of fishing and general family boating activities. 

“It’s these qualities that help make it an award-winning vessel in New Zealand.”

Judges at the Aukland Boat Show announced the Senator 500 the Boat of the Year and this latest version comes with the added attraction of being able to add and remove any of its multiple features. 

For instance, both seats can be removed by simply turning the wing nuts. 

They can also slide fore and aft if you are loading craypots on board. 

While Senator Boats call them bunks in the cuddy, they’re not big enough for sleeping purposes. 

Toddlers could have a kip in calm conditions while mum and dad wet a line. 

The ‘bunks’ are more of an upholstered bench seat and there are various configurations available. 

You could opt to leave one out and have a toilet instead. 

At the transom, there is a great idea with the live-bait tank. 

It comes with a swivel cutting board on top, which doubles as the lid to the tank and the whole structure can be removed to make extra room in the cockpit. 

The modular design makes it possible to add or remove many features. 

Come clean-up time, the cutting board section on top of the bait tank swivels to the left and over the transom to hose down with the deck wash. 

A shelf under the cutting board has two large tackle/lure/tool drawers. 

While the review vessel came with a 56-litre IceyTek portable ice box under the passenger seat, the live bait tank on the transom could also double as an ice box for drinks and foodstuffs for that family picnic. 

A second ice cooler (Kiwis refer to them as chilly bins) can also slide in under the skipper’s seat.

The bait station, transom gunwale, and side pockets of the Senator 500CU feature another great idea developed in New Zealand; the Railblaza storage system capable of taking various fittings. 

This system is what allows the seats to be slid forward and backwards to make more room in the cockpit. 

The aluminium rails are bolted to the side pockets and the seats can be removed. 

On the port and starboard side walls of the live bait tank, the Railblaza anchoring base plates can accommodate various brackets for fishing rods, plus the 500CU comes with two similar mounts on the forward port bow to hold an electric motor. 

This accessory anchoring system is a terrific addition and quite simple. 

The rails can be cut to any length and are streamlined so as not to catch or interfere as you move about the boat. 

I have had a similar removable rail system fitted in the cockpit of my plate boat for years and it accommodates scuba tanks, port and starboard. 

The rails bolt onto my side pockets in seconds and air cylinders are strapped in an upright position. 

Far better than having tanks rolling around on the deck. 

The Railblaza brackets can be used to stow rods, gaffs, boat hooks, etc, plus there are suction cap models to secure mobile phones and other accessories. 

The gunwale mounts take the adjustable angled rod holders. 

Heading forward, there’s a large hatch giving access to the anchor well and electric motor, if fitted. 

The well is big enough to accommodate a power drum winch however many anglers these days are happy with the usual anchor/chain/rope set up, instead opting to fit the electric troll motors so they can hover over a fishing spot. 

Of course, it all depends on where you choose to fish. 

If you’re in a windy location with strong current, the electric motor would be working hard to keep you in position. 

But for calmer waters, anglers are reporting good results by deploying the bow-mounted troll motor and staying on location. 

They say it’s much faster to move from one place to another. 

Having the fittings on the vessel ready to take such a motor is a big plus. 

The helm has a ‘no frills’ design, with the console fixed to the starboard wall. 

The review vessel had the twin digital Yamaha gauges on the facia, while alongside was the GME marine radio. 

The main power switch panel was located to port. 

The Garmin combo unit was mounted on the shelf behind the windscreen and here too were another pair of Railblaza anchoring points for accessories. 

The hull plates on the 500CU are 4mm aluminium, with 3mm metal used on the chambered collar. 

From the sharp entry, the bottom flattens to a transom deadrise of 18 degrees. 

These two features translate to a stable craft at rest on the water, yet one that is agile and fast moving underway. 

At just over 5m in length, the maximum power rating is 90hp. 

Sportsmarine feels the Yamaha 75hp is a very capable and economic match for this vessel. 
Performance wise, with a gusty easterly wind blowing across Koombana Bay off Bunbury and with the Garmin combo registering speed in miles per hour, the Senator 500CU topped 36mph at 5900rpm on the Yamaha gauge. 

Throttling back to just over 4000 revs, she skipped and boogied at a comfortable 25mph. 
The cockpit floor and wide side decks have the non-skid high-density foam decking for safety and it is easy underfoot for all-day outings. 

The unusually wide gunwales are handy for sitting on, plus it means the side pockets underneath are equally as roomy. 

In fact, the pockets run the full length of the boat, very handy for one-piece fishing rods that can be stowed using the Railblaza rod hooks. 

Senator Boats has been in production in New Zealand for almost 30 years and is considered one of the country’s leading manufacturers of plate alloy boats. 
As I said, don’t be put off by the unusual shape. 

They are designed with safety being the top priority. 

This latest 500CU took only days to sell.

NUTS & BOLTS

• Model: Senator 500CU
• Overall Length: 5.2m
• Beam external: 2m    
• Internal: 1.4m
• Floor to gunwale height: 615mm
• Fuel: 90 litres
• HP: Yamaha F75hp
• Tow weight: 750kg
• MANUFACTURER: Senator Boats; Napier, New Zealand.
• AGENT: Sportsmarine Boat Centre; 57 Strickland Street, East Bunbury, WA 6230; www.sportsmarine.com.au 
• PRICING: $86,997. The new owner paid extra for the fitting of the anchor winch, sound system, and dual batteries.

PROS & CONS

PROS

• Popular size, tough and agile.
• Sealed positive buoyancy chambers are an excellent safety feature.
• Roomy 2.2 square metre interior cockpit. 
• Rounded bow gets rid of water fast.
• Modular design allowing for add-ons according to budget.
• Wide side decks to suit anglers.
• Economic running.

CONS

• Don’t be put off by the pontoon style. You’ll be surprised by the agility and dry ride.
• Bunks not for sleeping; rather bench seating with good storage underneath. Room for a toilet if required.