Why good equipment can stop fitting the job without becoming bad equipment.
Why good equipment can stop fitting the job without becoming bad equipment. Fins affect propulsion, trim, foot position and even how easy the diver is to move on land, so I treat them as tools rather than fashion.
What the fin changes
The Go Sport was once my everyday fin when I was spending a lot of time taking customers through the water. Its great strength for me was speed: I could get it on quickly and get moving.
As my diving shifted further toward sidemount and technical configurations, other fins solved my current problems better. That does not make the Go Sport a failure. It makes it a marker of an earlier phase of my diving.
The practical point
The right fin is the one that makes the complete diver easier to control, not the one that wins an argument online.
A good product can simply lose its job
The Scubapro Go Sport used to be my everyday choice when I was guiding clients because it was quick to put on and practical. As my diving and preferences changed, the RK4 took over that role. I now use the Go Sport rarely.
That is worth documenting because equipment reviews often pretend every purchase remains a favourite forever. Sometimes a product did exactly what I needed for years and then another design fitted the new mission better. That does not make the earlier choice a mistake.
Fins are propulsion, trim and ballast at the same time
The blade produces thrust, but the fin also changes the mass and buoyancy at the end of the legs. That affects trim. A fin that feels wonderful with a thin wetsuit can make another diver excessively feet-heavy in a drysuit, while a deliberately heavy fin can be useful when a drysuit configuration tends to make the feet float. This is why I own several pairs instead of expecting one design to dominate every dive.
My Apeks RK4 is the everyday sidemount choice. I like the technical-style short blade, the near-neutral behaviour I experience in the water and especially the large spring-strap geometry: with sidemount cylinders beside me, reaching the heel can be less convenient, so a strap that is easy to grab matters. For demanding technical diving I may deliberately choose the much heavier, negatively buoyant Hollis F1—the “Batman fins.”
Technique matters more than catalogue language
Frog kick, modified frog, back kick, helicopter turns and careful positioning near a silty bottom ask different things from a fin than straight-line flutter kicking. A stiff, compact blade can translate small ankle movements into controlled thrust, but stiffness also costs muscular effort. The useful question is whether the fin works with the diver’s technique, suit and mission.
DPV use introduces another interaction
When a DPV is pulling the diver, the fins are still in the flow and still influence body position and drag. I have found the TUSA Tri-Force particularly pleasant in that context. That is a personal observation, not a laboratory measurement, but it is exactly the kind of detail I care about: not just how the product feels on a shop floor, but how it behaves inside the complete system underwater.
The fin test I care about
I want to hover, frog kick, back kick, turn and stop without the fin fighting my ankles or changing my trim in an unwanted way. I also want to be able to put it on and remove it in the real configuration, with cylinders or a drysuit limiting reach. That is why a strap handle can matter to me as much as a blade feature.
Explore related topics
This article stands on its own, but these pages go deeper into the parts that connect directly with it:
