If one is to believe fin advertisements, a range of
improvements, from modified Venturi openings to split
blades, provides such advantages that one ought to be
able to power through a five-knot current without breathing
hard. As we pointed out as far back as 1991, typically
the larger the fins, the more thrust they offer, while the
many “innovations” made are largely to differentiate models
in advertising. Nonetheless, there can be differences,
so Undercurrent has compiled some recent comparative
studies of fin performance. Although experts don’t always
agree on which fins are best, some do stand out.
Britain’s DIVE magazine recently tested
several models to compare the thrust they
produced versus the effort required. Longdistance
cyclist and diver Steve Moss, who is
accustomed to maintaining a constant effort
for prolonged periods, tested the fins. He
attached a bungee cord to his waist, with
the other end attached to a calibrated scale.
Other testers concentrated on the fins’
maneuverability, fit, comfort, buckles and straps. They
also tried alternative kick styles and surface swimming.
In the end, DIVE’s chief equipment tester, Charles
Hood, noted that all the fins were acceptable but differed
in durability, maneuverability and power. He recommended
that buyers “base your choice on the type of diving
that you are doing and on those fin qualities that suit that
particular diving.”
Imprex the Top Performer
The top performer was the TUSA Imprex Tri-Ex with
a modified solid blade, rated 9.5 out of a possible 10.
The magazine reported, “It produced a huge force when
power was required.” All test team members also found
the Imprex “by far the most comfortable fin tested,”
primarily due to the soft material employed in the generous
foot pocket. Being lightweight, the fins proved highly
maneuverable: “certainly as good as the leading split fins,
and great for snorkeling.” Midpriced at $89, they represent
“pretty good value for money,” according to the
testers.
Neither the blade material nor the use of flanges,
longitudinal splits, vents or ribs increased the
velocity of water down the fin and, in fact, may
decrease it, thus lowering thrust and economy. |
And while there are those who love to hate the Force
Fin, the Extra Force Fin with its distinctive swallowtail
blade compared favorably. Though the heel strap broke
near the end of the test, DIVE reported, “The thrust is
remarkable, and they are a delight while frog kicking.
They represent the ultimate in fin technology.” However,
Undercurrent wonders who would pay the absurd list price
of $495.
Apollo’s Bio-Fin Pro, the prototypical
split fin design, was also highly rated for
comfort and maneuverability, but less so
for thrust. “If agility rather than brute
force is your criterion, you should definitely
consider these fins,” DIVE observed.
Of other split fins tested, the IST Talaria
was easy to fit, easy to walk in and highly
maneuverable underwater. “As for performance,
they are everything you would
want,” the testers agreed. The full-foot
Scuba Pro Twin Speeds, while positively
buoyant, were heavy but felt “robust and
well made,” said Hood, adding, “If you
dive in a tough environment, these fins
are definitely worth considering.” The
Aeris Velocity Duo was deemed a “good
all-round midrange split fin” but lost out
to the Twin Speeds because they produced
less thrust.
Quattros Lag the Leaders
The Mares Avanti Quattro came in
just behind five other fins. The editors
said the Quattros were comfortable and
powerful and “made us feel agile while
maintaining good control.” The Atomic
Split fin, also based on the Nature’s Wing
design, was described as “heavy and disappointing
in terms of thrust,” earning a rating
of just 7 out of 10. Said DIVE, “There
are better split fins out there, which are
better value for money.” Also rated 7 out
of 10 were the Seemann Xdrive Pro, Deep
Outdoors Six-Gill, Beuchat X-Jet and
Typhoon Tornado.
Another British publication, Diver,
tested Apollo, Atomic and Quattro three
years ago (reported in the August 2003
Undercurrent). Diver technical editor John
Bantin reported that the Apollos and
Atomics performed identically on the
speedometer in ocean tests over a short
course. One tester noted that he could
start finning at high speed right away
with the split fins. “With the Quattros,”
he reported, “I felt as if I was starting in
a higher gear, with more pressure on my
calf muscle.” Bantin favored the lighter weight Atomics
over the Apollos. The Quattros lost because of their extra
size in the water, in the boat and in the bag.
DIVE gave the retro-looking black rubber vented IDI
Power Fin the same rating as the Quattro (8 out of 10).
At a retail price of $75, “these fins give incredible value
for money,” said DIVE, adding, “You might be forgiven for
thinking these are split fins, as they perform in a similar
fashion, due to the soft inner section of the blade, which
allows the two outer sides to move independently of one
another.”
It’s All in the Kick
With the single-bladed Imprex, Quattro and Power
Fin performing competitively with top-of-the-line split-fin models, we want to point to a study reported in the
January 2004 Undercurrent that determined that no single
design (split or single blade) was inherently better than
the other.
More important than any single design feature was the
correlation between fin stiffness and hip angle, reflecting
a deeper kick and resulting in greater distance of travel
per kick. Researchers from State University of New York
at Buffalo also determined that the neither the blade
material nor the use of flanges, longitudinal splits, vents
or ribs increased the velocity of water down the fin and, in
fact, may decrease it, thus lowering thrust and economy.
The Buffalo researchers also pointed out that women
have significantly lower muscular force than men, so the
best fin may be different for women. As we reported in
February 2004, for women the most economical fins (i.e.,
lower energy required when kicking) were the Apollos
(either split or taped to make them single-bladed) and
the rigid Attack fin (now discontinued and replaced by
the Sporasub Instinct full-foot freediving fin), with all others
performing similarly to each other. The taped Apollo
fin (solid blade) was much better at faster speeds (24 percent
higher than the Attack).
Which Is the Fastest?
Professor Jim Grier, a tester for ScubaLab, has found
that air consumption efficiency and static thrust highly
correlate to average maximum speed. Grier performed
open-water speed tests as the criterion for ratings. As a
baseline, he selected his own Apollo blue fins, with which
he could average 3.25 mph. Grier found that he was able
to exceed his Apollo’s average speed with the Aqua Lung
Caravelle, Oceanic Caribe, Oceanic V6, Scuba Pro Twin
Speed, TUSA FF-9 and Mares Volo-Race.
ScubaLab’sTM Testers’TM Choices
More recently, ScubaLab’sTM fin testers awarded their
2005 Testers’ TM Choice designation to the Apollo Sports
Bio-Fin Pro Yellow/C-Series, the Deep Outdoors Six-Gill
and the Aeris Velocity Duo (all also rated highly by the
editors of DIVE), plus the Mor-Fin Blue Vt-300b among
open-heel fins. Among full-foot fins, Testers’TM Choice
ratings were bestowed on Atomic Aquatics Splitfin and
the Akona Azione.
And the Consensus Is . . .
Those singled out more than once for excellent performance
included various models of the Apollo Bio-Fin,
Scuba Pro’s Twin Speed, Atomic Aquatics’ Splitfin, and
the single-bladed Mares Quattro.
If there seem to be some inconsistencies in the results
of these studies, remember that researchers tested different
models and brands, at different times, using different
technologies. But it’s also because in the end, fins must
be judged personally. All the vents, splits, flanges and
stats aside, it’s how they feel on your feet and how well
they serve the purpose of your diving.