Cobra Cat 640

Tested by Erwin Bursik (SKI-BOAT September/October 2006)


A NEW CobraCat is born! The first CobraCat 640 was recently water tested then given to me for a formal review during late June. When I first saw the completed craft outside Mallards’ factory, the day prior to the test, she looked extremely large and very striking, standing alongside a number of CobraCat 525s.

However, I was more taken aback by the transformation from the final “plug” that I had seen when Mike Barnes asked me to come and see how the prototype performed on Durban Bay. The ugly duckling had become a swan.

Being in on the conceptual stage, and then having the first fully completed CobraCat 640 presented to me for review, certainly increased not only my interest in the craft, but also gave me an added appreciation of what goes into a new craft from Mallards.

The CobraCat 640 is to be marketed as the upgraded 2006 model of the CobraCat 625, which was initially tested in SKI-BOAT magazine in January/February 1999. This slightly longer boat, with a number of substantially redesigned hull features, embodies the essence of top-of-the-range traditional ski-boats in South Africa, the archetype for offshore big gamefishing.

The CobraCat 625 was accepted as the marlin ski-boat at Sodwana Bay up until newer craft were introduced that were more sportfishers than ski-boats. Mallards, however, are of the opinion that there is a market for a large ski-boat designed largely for the top end of the sportfishery that can be towed and deployed off the beach with a reasonably sized 4×4 vehicle. Furthermore, the craft should have both the handling characteristics and the cockpit area necessary to fight big marlin in the varying heavy sea conditions experienced off our coast.

After spending a morning on the CobraCat 640 in sea conditions that were unusually rough for this time of year, I am of the opinion that with this express model large ski-boat, they have achieved what they set out to do.

Indeed, the CobraCat 640, a 21ft ski-boat, is one hell of a boat. So much so, that having looked at her on the trailer, seen her at sea and then having spent a good deal of time putting her through her paces, I queried her overall length with Geoff Barnes. He was adamant that the craft’s length is 21ft, but being the doubting Thomas that I am, I asked the same question of Mike after we had retrailered the craft. He again confirmed that the overall length is 6,4m — exactly 21ft.

So now I’m convinced, but all I can say is that the CobraCat 640 is a hell of a big 21ft ski-boat.

Geoff explained that by adding buoyancy to the bow area of the sponsons, and by widening them during the redesign, Mallards was been able to move the helm station quite a lot further forward. This effectively increases the working deck area, while moving the crew’s weight forward when running.

A further major change is that of raising the gunnel height to almost that of their seven-, eight- and nine metre sportfishers. I am particularly enamoured of gunnel heights that are well over the average man’s knee height. It makes working the deck while marlin fishing that much more practical and safe. If one is working the riggers, leadering fish, tagging or gaffing, the extra support afforded by high gunnels, especially in big seas, is practically essential.

The photoshoot took place quite a way off Durban beachfront, in a sea that had a surprisingly heavy, easterly swell, capped by a chop created by a moderately strong north-westerly or land breeze.

While watching her from every conceivable angle as she performed for the cameras, and for the moment ignoring her very striking looks, it became apparent that this big ski-boat rides the sea extremely well with a very prone stance to the sea. In other words, she uses her built-in hull design features to optimise her ride when on the plane, rather than relying heavily on the motor trims.

Talking of motors, Mallards had selected twin Mercury Optimax 135s to power the test model. The motors were spinning 19-pitch, four-bladed stainless-steel props. Even though these motors were so new that they were still on double oil mix, they provided more than sufficient power to make the CobraCat 640 perform superbly.

Eventually I had to leave the comfort of Shooting Star, a CobraCat 800 photograph boat, to face the sea in the express CobraCat 640. The crossing from boat to boat in that sea was, to put it mildly, interesting. However, thanks to the flat-topped gunnels which were basically the same height above the water, I was able to step across, using the very substantial stainless-steel support of the 640’s T-top as my sole support. In spite of my weight, Tony Molenaar’s immaculate stainless-steel work didn’t bend or break during the transfer — indeed, it didn’t even flinch.
Once behind the wheel in this craft’s very well protected helm station, it was my turn to see what the CobraCat 640 could do in the conditions the Indian Ocean had presented us with.

With four of us aboard, I eased the throttles forward and stuck her bow into the oncoming swell. Having trimmed in her motors completely, I began adjusting them as I added power, in so doing pushing the craft onto the plane. I was setting a course towards Middle Reef, an area where a few ’cuda had come out during the previous four days. With the sea now slightly on the starboard bow, I watched the SOG climb on the top-of-the-range Lowrance sounder that had been installed in the test boat. Settling at about 17 knots with the rev counter showing 3 400 rpm, we were making very good headway. Those of us aboard were comfortable enough to be enjoying the ride.

I found that initially I was over-trimming the motors in an attempt to maximise the comfort of the ride, instead of letting the hull adopt its natural planning ride in this uncomfortable sea. From the trim perspective, I eventually settled on minimal bow-up trim, thereafter applying only a marginal adjustment to laterally stabilise the craft in this not-so-nice sea.

After about five kilometres I felt I had come to grips with the CobraCat 640 and swung her bow around to run in towards the coast, so in effect I was running along the crests of the north-easterly swell. She loved it, and I was able to push up what I call the “comfort speed” to over 20 knots with revs at 3 800 rpm. During both of these trial periods, which take the most out of any craft, I experienced no spray and no wind as the deflector capping on the top of a relatively high windscreen gave me excellent protection.

Full clears can be fitted as an extra between the top of the express-style windscreen and the substantial hard T-top that comes with the craft. This would provide total protection within the confines of the helm station — a definite boon for those longer runs to the tuna grounds off Cape Town, as well as in the beastly easterly seas and rain squalls off Sodwana during the marlin season.

Running directly with the swell, especially a big lifting sea,  is probably the most difficult, telling situation for any smallish craft. Running with the north-easterly swell that lifts over the Kinmount Bank off Durban beachfront gave me the opportunity to see how the CobraCat 640 reacted in the following sea, and also allowed me to spin her around in all directions to ascertain what she would be like in the surf.
Lifting her bow up as much as I could before the props started to cavitate, I ran her down the wave faces at high speeds with little effect on the hull-over-water performance. The only effect was that the north-westerly wind marginally lifted her starboard side via its influence on the T-top and the trimmed-up bow.

When I was throwing her into tight turns in these almost cresting swells, I was amazed at how easily she came about for the big boat she is, and that she showed no tendency to cavitate. I was also pleasantly surprised at her out-the-hole performance. With 135hp motors swinging 19-pitch, four-bladed, cupped props, it’s asking a lot for a motor to generate the torque necessary to do this. But the Mercury “Opties”, as they are affectionately known, did just that — and with seeming ease.

In order to fully judge her pedigree, all that was left was to try her out in the rough stuff at the various trolling speeds — slow on one motor, right up to the 6,5-8 knots required for trolling konas for marlin. Seeing as a craft of this size is going to spend the majority of her time at sea trolling, this becomes a very important part of my review. Not only do I look for general ride comfort — lack of pounding or sideways banging — but also protection from wind and spray when trolling in a short, sharp beam sea.

The CobraCat 640 passed with flying colours. I tried sitting and standing in all the normal positions while spending those long hours at sea, watching lures or baits while trolling for marlin, and found both comfort and protection. Of course, it would be even better with clears installed.

There are a few questions I hate to hear people ask when talking boats. One of them is, “What’s her top speed?” This really means nothing, for one very seldom gets to use the top speed at sea. However, for the speed freaks who love to damage their boats and crew, the CobraCat 640 topped out at 34 knots on Durban Bay, and at sea I got 26 knots at just under 5 000 rpm.

As far as creature comforts go, the CobraCat 640 has all that one normally desires when buying a large ski-boat. Mallards have also incorporated many of the ideas they have perfected on their large sportfishers to ensure this craft satisfies the “dream boat” criteria of the aspirant buyer.

As I said earlier, the helm station is situated well forward. Ahead of it is an area big enough to be called a “cabin” that one could comfortably crawl into for a sleep. However, more importantly for Geoff at least, this area will stow 130 lb banana butt outfits with ease, resting on the upholstered “bed” floor of this locker. There is also enough space to store all the life jackets and other safety gear under this base.

The helm station itself is well designed in the typical CobraCat layout that has passed the test of time — lots of it — at sea.
What I also mentioned earlier was the impressive size of the fish deck or cockpit area. It’s exceptionally large, and apart from all the benefits already mentioned, it has a mounted, big, heavy-duty fighting chair. The sizeable area, however, permits crew working the deck to pass around the chair without it getting in the way.

Have a look at the photographs of the false transom area — with its livebait wells and marlin gate, as well as storage lockers — and you will agree that this craft has everything a ski-boat angler could desire. By the way, the rounded aft corners provide sufficient area to situate a Luna tube in each corner, if required.

Rod racks situated in the under-gunnel sides of the craft cater not only for short boat rods and gaffs, but also for longer whipping rods. Tip section space to accommodate these rods has been allowed behind the internal helm station panelling.

Finally, the T-top with its rear-mounted rocket launcher-style rod holders is superbly designed and extremely well constructed, with magnificent stainless-steel work. It not only supplies the shade required during long hours of searching for marlin, but also looks great and doesn’t appear to have a great deal of effect on the craft’s ride at fast speeds.

The entire Mallards team can be extremely proud of this, the latest CobraCat produced at their Pinetown factory. She carries with her the immaculate finish associated with all Mallards’ boats, aspects that are far too numerous to elaborate on here, but which clearly show the expertise of many decades of offshore craft construction for which Mallards are renowned.

Considering her size and performance, I believe the CobraCat 640 will suit those anglers who want an easily trailerable big ski-boat to pursue big marlin and tuna off southern Africa’s east coast and off Cape Point. Yes, as I said, she’s one hell of a boat!

Show More

Related Articles

Leave a Reply

Back to top button