Concept Test
Delta Force Wave and Freeride Fin

A powerful new fin with potential for certain wavesailing use, and a viable alternative to traditional weed fins for shallow water locations.

Maui Ultra Fins are no stranger to producing innovative foils, notably with their original outline shapes. Now Aeronautical Engineer Rick Hanke’s brand, that gave the world the elliptical wave fin, bring you the Delta-shaped profile.

If it’s good enough and manoeuvrable enough under high Gs for fighter jets then logic dictates the Delta will turn like a MiG and be as fast as a Superfighter. Our mind-sets, hard-coded on porpoise-profile fins, are surely capable of accepting of a Delta shape - perhaps for Speed or Freeride use – but what about out in the waves? MUFC sent us a wave prototype (169mm) that is essentially a US Box version of their smallest Freeride model. MUFC quote these fins are equivalent to one of double that length. At the time of publishing this is not a finalised product, but Slalom, Speed and Freeride versions in Powerbox and Tuttle versions will hit the shelves end May 2012.

First Outing
We first tested the Delta on an older fashioned single fin wave board – more as it was the only single waveboard to hand - plus were were supplied a US Box prototype branded as and intended for wavesailing use. (Otherwise identical dimensions to their 160 Freeride model). On the longer waterline length and narrower outline of the dated board the fin took a little getting used to, but it was marginally faster than the usual single fin used in this board, especially when a tad overpowered – mainly due to the load the extra thickness and width of it could take, plus the shorter depth.  

Compared to Multifin
Although it coped well in more powered conditions it required patience to plane-up in more marginal conditions. Expecting to rise up on the back foot, the fin drove the longer nose down into the water, more like a multifin setup, and was fractionally harder to point upwind. That’s in terms of feel. Head-to-head upwind it could well have been comparable but in terms of get-up-and go it was definitely less efficient than a deeper fin.

In smoother water, once planing, it took lots of push - there’s loads of surface area from the extra width offsetting the lack of depth - and was hard to spin out. In choppy sea it was a little slippy from time to time. It’s an odd feeling. The lack of upwards drive and the fact the board doesn't feel like it's sailing on just a deep a fin alone means the board sticks to the water more and re-connects with the surface quickly when it does skip free, but, unchecked, it could slip out in bumpier conditions as it’s shallower depth lets go sooner than a deeper fin.

When it came to jumping it was positive, releasing better than a multifin cluster as you might imagine, but not quite as poppy as a higher aspect ratio standard centre fin shape. For Freeride use it will definitely be better for jumping than a deeper, more upright fin. As with multi-fins, in overpowered conditions this would be much less relevant. The only other point worth noting is that, although it’s heavier than a traditional single fin - the thing is pretty thick and wide - it’s lighter than 4 fins but delivers a similar feel.

Fiddly Fit
The model we tested (16.9 cm - quoted as being equivalent to a ‘normal’ fin twice that size) was a US box and was awkward and time-consuming to fit and adjust (when windy!) due to the 3 screws involved to handle the overlap with the leading edge going forward of the box. It was hard to get a tight fit, and to be honest I would fear for the box itself on impact and also worried about bending or snapping screws.

Regardless, a Powerbox version would be much more suitable – probably limiting this size to larger Freestyle wave boards then. However, for wave use the adjustability of a US box is undoubtedly preferable to adjust how close or far the trailing edge can be to the tail. Also, boards with more pronounced tail Vee might represent a problem with the extra overhang forward of the box, despite rubber padding adhered to the overhanging front edge to protect the underside of the board.

At the time of publication we were informed that it will only come in Tuttle and Powerbox versions, with the 'wave' model (read US Box) on hold and production versions of the Freeride, Slalom and Speed versions available in Tuttle and Powerbox from end May 2012.

Modern Outline Boards
Installed on 5-box more modern wave board of similar volume it came into its own a lot more. The flatter sailing, more nose-down feeling was expected and matched the shorter board outline better - a smoother ride without the nose driving into chop ahead - and the modern rocker delivered the option of loading the back foot a little more like a single fin to get going. Off the wind it was, of course, noticeably faster than the same board in 3 or 4-fin mode and about the same in terms of pointing as a Quad.

Turning
And now the bit the wavesailors will really want to know about. It definitely has more drive than a regular single fin. That is, to pump mid or low face for speed when riding and also out of turns. There’s no real lack of pace or bite for drawn out arcs in larger, faster surf, and it interacts with the lip quite well and always feels like it will come around OK. It has potential to slip in tighter turns in choppier water but to be honest on a messy face it turned tighter than a regular single on both styles of board – probably because the leading edge on the US Box starts further forward – so any tendency to lose grip is because you can push it harder. That’s probably relevant to most powerful fins regardless of plan shape.

If you’re a single fin fan and like to wavesail on the rail it’s great and more forgiving in unintentional tail slides off-the-top, such as in onshore frontside riding conditions, than a standard upright single fin, but requires full commitment compared to a Quad. It does climb the face vertically well in medium, overhead surf at speed, but not as well as a Twin or a Quad. Moving it back in the box gives a more dramatic effect in terms of increased grip than the equivalent movement of a higher aspect fin - this suggested it was more suited to larger faster surf than onshore messy conditions.

Who’s it For?
Bigger, more powerful riders who like to push their back foot and go faster, would suit die-hard single fin sailors upgrading to convertible multi/single fin boards and riders of all weights used to multifins on lower volume boards on their larger Freestyle Wave toys. Its main use of course will be at weedy, shallower spots.

Plus Points
Drivy multifin feeling. Faster than 2, 3, or 4 fins. Tight turning arc in smoother water.

Minus Points
Heavier than a regular single fin. Hard to match use with boards of suitable fin box type. Not so good in onshore riding or pointing.

Summary
An interesting concept, but probably limited for now in terms of all-round wave use and more applicable as a freestyle/wave or Freeride anti-weed fin or as a solid foil for larger riders in larger, clean waves and shallower reefs – perhaps limited to bigger custom waveboards with Powerbox fins. The one question we were left asking ourselves afterwards was ‘what about 2 shorter versions of these placed as sidebites to regular fins or even near the rails on a wider tail as a twin keel fin fish-style setup?’ BM

More info at: mauiultrafins.com