Efficiency while finning is the most important characteristic of swim fins. In the water divers want to expend the least amount of energy possible while kicking at all frequencies in order to travel further and use the least amount of air. Over the last hundred years, feature colors and vents, splits, hinges, battens, winglets and skegs are marginal changes that have been incorporated into old fin designs. The shortcomings of such fins is that they are all just spineless, wormlike fins. Truefin, with it's artificial spines, was developed over seven years through multiple iterations of design. Early in the design process Truefin's performance easily surpassed spineless fins during machine testing. Being unchallenged by prior art, prototype design refinements focused on the goal of improving the next generation of Truefin over the previous generation of Truefin.
During flutter kicking with Truefin you will go faster at higher kicking frequencies and/or at a greater range of kicking motion and reach a terminal velocity only after the user has insufficient strength to kick faster. Diminishing benefits occur at ever increasing exertion because the user encounters drag proportional the square of velocity of the diver moving through the water. A powerful flutter kicker will never be able to cause the Truefin blade to collapse and go flat. During modified flutter kicks the user may directly push the Truefin blade flat rearward against the water also without causing the blade to collapse.
During frog kicking the best technique is to glide to nearly a stop during the return stroke, and then allow the blade to flatten prior to pushing rearward and executing the frog kick power stroke. Although Blue spines are excellent for frog kicks, professionals may prefer Green spines for maximum frog kick glide distances. Users of Truefin have reported that they have experienced the longest frog kick glide distances of any fins they had previously used, even when Blue spines were installed.
During dolphin kicking with Blue spines Truefin is highly efficient and significant thrust is possible during the power stroke while the blade flexes 'toe down' sixty degrees with Blue spines or Green spines. During the return or recovery dolphin kick phase, the twenty degrees blade flex in the 'toe up' direction with Blue spines or the zero degree blade flex in the 'toe up' direction with Green spines, may also contribute to propulsion if the user has sufficient strength.
During side kicking or breast stroke kicking, the twenty degrees 'toe up' blade flex limitation with Truefin Blue spines improves efficiency during the power away kick, while during the forward return phase of the side kick the blade advantageously flexes 'toe down' sixty degrees while minimizing return kick resistance.
During reverse or back kicking while wearing fins, generally the traditional recommendation is for the side walls or side rails of scuba fins to be used for backward propulsion while the fin blades are kept parallel with the water surface or the sea floor, and while a relatively rapid backward side slicing motion of the fin occurs. Truefin also recommends this technique. The side rails of Truefin are similar in size or side projected area as the relatively large side rails of traditional stiff technical fins. Note that the side rails of Truefin also offer a benefit when helicopter turning.
During surface swimming with Blue spines, and particularly while swimming face up while on the user's back, the highly flexible nature of Truefin toward the sixty degrees 'toe down' blade flex limit is efficient and minimizes splashes, while blade flex in the twenty degrees 'toe up' direction enables the user to exert limited propulsive forces if desired during the rearward return stroke of a surface flutter kick.
During endurance flutter kicking on the surface (or underwater), while executing the return stroke the user is encouraged to relax the user's ankle and allow the fin blade to follow the streamline of the water as this promotes blood circulation in the foot and ankle and minimizes muscle cramps. For those who have hip, knee, or ankle injuries, Truefin users have reported a reduction or elimination of general soreness and pain such users typically experienced at the end of a diving day while using traditional spineless fin of their choice. This benefit of Truefin may be attributed to the general efficiency of Truefin, as well as elimination of the effort required to flex the solid elastomeric rails of traditional spineless fins.