Owners Manual

For a greatly expanded and updated technical Owners Manual, please DOWNLOAD THE MANUAL

Condensed Manual:

TRUEFIN has been designed to provide you with the best finning experience available. In order to maintain its high performance, please consider the following instructions to keep your fins in optimal condition.

Care and Maintenance

• Avoid exposure to flame or excessive heat. Continuous and direct exposure to the hot sun is not a problem.

• Store fins flat - If fins are stored in a folded configuration, after unfolding and installing the spines, Truefin may be used immediately without loss of performance, and it will readily seek the original ‘as molded’ shape upon kicking. If it is desired to accelerate the Monprene relaxation toward the original ‘as molded’ shape, fold Truefin in the opposite direction briefly before installing the spines. When installing spines, always ensure that the hash marks on the spines are adjacent to the hash marks on the fin, and that the tear drops on the spines are adjacent to the tear drops on the fin.

TRUEFIN Model 110 Warranty: Limited Lifetime (excluding heel straps)

SIZE CHART: Only a size LARGE is currently available.

If you have a men’s size 13 with a large foot shape, Truefin size large may be too small.

Disassembly

If the fins are to be disassembled for repair or for travel, each spine may be removed by pressing both red spring lock pins simultaneously while utilizing the spine removal tool, or utilizing two small blunt objects, while pushing the end out with the index finger or thumb of the other hand, and withdrawing the spine from the fin rail. A spine removal tool is included with every pair of fins.

ABOVE: Utilizing the ‘C shaped spine removal tool’ to press the red spring pins. Youtube vidoe: Removing spine

BELOW: Truefin may have been shipped with any one of the below spine removal tools. These tools have all been 3D printed, and from left to right are old to new tool designs. Once the final design has been approved it will be injection molded. In the absence of a tool, two blunt objects may be used. We increased the spring tension so simply directly pressing with ones fingers is now very difficult.

BELOW: Utilizing two ‘button spine removal tools’ to press the red spring pins while bending the fin as shown and pushing the spine out with the left thumb. Any one of multiple 3D printed versions of the spine removal tool has been included with all fins sold, and a final version of the spine removal tool has not yet been approved for injection molding as of 10/2022. It is difficult to successfully press the red spring pins by hand without the use of a tool or two blunt objects. Most users will never remove the spines unless they are customizing the fin or wish to fold the fin up during air travel.

BELOW: Vertebrae blocks may be separated from spine as desired:

To reassemble standard configuration fins, ensure the three hash marks (III) at each vertebra are orientated down toward the platform of the fin (or sole of the users foot) and with the tear drops ( 💧) orientated up as the spine is assembled, and slide spine into the fin rail until red lock pins engage fully with the fin shoulder holes. Hash marks of vertebra are to be installed adjacent to the hash marks at the bottom of the fin rails, and the tear drops are to be installed adjacent to the tear drops at the top of the fin rails.  End face of base link should be installed flush with the angled end face of the spine receiving banded tube in order to offer the best streamline profile. Note that this base link may be installed at either of two orientations and will still function and effectively lock the spine in position.

Note: The individual vertebra of the Truefin spines, as well as the monprene fin of Truefin, are all provided with mold date wheel inserts in order to track the date of manufacture for quality control purposes.

Travel Packing

The spines may be unlocked and removed from the fin upon pressing the polymer red base spring pins, while pushing or pulling the spines out of each rail. Removal of the spines enables the user to bend Truefin into a 'U' shape when traveling if it is desired to minimize the volume of the shipping package. Once the spines are removed, the spine vertebrae may be separated and packaged as desired. It is currently suggested to not store the fin for an extended period of time in this travel configuration. When bending Truefin into a 'U' shape, or alternatively when rolling Truefin up, try to maintain as large a bend radius as possible of the pass core fin rails when packing to fit inside luggage bags or containers. A temporary 'set' may be observed when unrolling Truefin from the travel configuration, and the user may wish to flex the 'unspined' fin in the opposite direction to remove this set, although practically such temporary set is of no consequence to operation and the fin will soon relax and restore itself to the original molded shape. Monprene is a very durable material, and during testing Truefin has parked a fully weighted car tire on top of the folded region of the Truefin blade and there was no functional damage. For a video of a truck parked on top of the folded region of Truefin, please visit the Truefin Youtube channel. Direct link: https://www.youtube.com/watch?v=fHkoYSlOTy0

Entering Water with Truefin 

When entering from shore, it is suggested to install the fins on the user's feet after the user has entered water at least waist deep, and remove the fins from the user's feet before exiting from shallow water.  In order to free the user's hands it is suggested to thread a cord or other flexible member through the heel straps and clip the cord to a 'D' ring secured to a vest or the Buoyancy Control Device (BCD).  Alternatively, a wading entry procedure may be performed from a beach or shore, where the user wades out toward the dive site while backwards shuffling feet to avoid stepping on rocks.

Follow standard entry procedures known in the scuba industry, such as back roll or seated entry method when entering off of relatively low platforms, or from ribs or zodiacs. 

For all entries off a boat, regardless of the method, ensure the BCD is sufficiently inflated and have the regulator in your mouth and operating, and with at least one hand holding your regulator and mask in place when you strike the water.

For relatively high platforms or decks, giant stride entries may be performed, however a fin may be forced off of a user's foot while the heel strap spring extends and the foot slides out of the flexible foot pocket, although the fin will still be secured to the user's leg as the fin strap slides up the user's calf.  If a user typically enters water off of high platforms, the user may wish to minimize the likelihood of a fin slipping off the user's foot by using non-elastic heel straps (ratcheting or universal style).

For experienced divers, when entering water off high platforms, the forward roll method may be performed. This generally involves standing at the edge of a boat deck, while the BCD is sufficiently inflated and regulator in your mouth and operating, and while having one hand on your mask and regulator and your other arm around your other equipment to avoid these from hitting you as you enter the water, and bend completely forward while imagining touching your feet with your fingers, and tucking your head and body into a tight ball while pushing yourself away from the boat with you legs, and while allowing the tank or tank valve region to strike the water first.. 

When snorkeling, generally all methods may be satisfactory because the user is not burdened with heavy tank(s) and other apparatus weight. 

Avoid walking forward through shallow water while wearing fins.

NOTE: Spring or bungee style heel straps should not be used when jumping out of helicopters. If this is an expected activity, first contact Truefin for more information.

Spine Replacement

Truefin Model 110 includes: one pair of black fins, with four installed Blue '412 spines or four installed Yellow ‘415 spines, depending on the user selection.

Fin and spines have a limited lifetime warranty.

Continued attempts to optimize the artificial vertebra with FEA and injection moldable material are ongoing to produce the highest performing spines at the lowest cost possible.  Current spine vertebra are injection molded glass filled 21,000 psi nylon 612.  Because spines have a lifetime guarantee, if real world service life is considered unsatisfactory then Truefin may elect to mold the spines with carbon fiber filled nylon (31,000 psi tensile), or make other material or geometry changes. Refer to ARCHIVED BLOG/ENDURANCE TESTS and Refer to TESTING - Bench Break Test

Having said that, it should be pointed out that the user should avoid causing premature failure of the spines by prying or kicking the spine against an immovable object both in water or on land because the spines are made out of plastic and glass of approximately bone hardness.  Typically, if a spine is subjected to a load consistent with kicking or prying against an immovable object, the design draft angles of the vertebrae will cause the vertebrae will laterally slide out of position while one of the Monprene passcore bands deforms. If this occurs, no damage has occurred and the spine may be reassembled. Furthermore, as indicated elsewhere in this website, if a spine breaks due to accident or abuse, the fin will generally perform as a traditional fin while only having one spine to enforce a compromised 'angle of attack'.  Contact Truefin for free replacement of spines if a spine breaks.

Sizing

Size - LARGE

LARGE is the only size currently available. Medium size is the next size to be produced, with a current launch date of 6/2023.

Dimensions below are in inches.

SIZE LARGE

Heel Strap Post

Truefin’s heel strap posts are industry standard 'large posts' and accept different styles and brands of common fin straps.

Truefin Model 110 size Large is shipped with Trident R559 Medium Standard Spring Style Fin Straps with Quick Release Side Tabs (www.tridentdive.com). Note: Some users prefer to use (for example) Trident RPH64 Universal Fin Straps, or ratcheting Trident RP48 fin straps generally available at divestores throughout the US.

This size chart is for Truefin Model 110 Large (L) and is for general reference only.  Foot shape also effects fit. Also, some users may adjust the fit of the fin by wearing thick wool socks, or 2-3 mm neoprene socks inside the boots. Note that wool generally does not compress at depths.

Foot Size: When used with:

Mens 9, 10 - Womens 10, 11 Dry Suit Boot

Mens 10, 11, 12 - Womens 11, 12, 13 5mm Boot / Dry Suit Boot

Mens 11, 12, 13 - Womens 12, 13, 14 3mm Boot / 5mm Boot

LIMITED LIFETIME WARRANTY

TrueFin, LLC (“TrueFin”) warrants to the original end user customer (the “End User”) that all new TrueFin products (the “Equipment”) shall be free from defects in material and workmanship. TrueFin warrants to the End User that Equipment that proves faulty by reason of defects in material or workmanship or is made inoperative during normal use by the End User for its intended purpose will be repaired or replaced by TrueFin. The End User acknowledges that normal use of the Equipment for its intended purpose shall, in all cases, be subject to any instructions and guidelines provided by TrueFin governing the appropriate use or operation of the Equipment. TrueFin will, at its option, either repair or replace any faulty Equipment on an exchange basis, with new Equipment or Equipment refurbished to be functionally equivalent to new Equipment. If TrueFin, in its sole discretion, is unable to repair or replace any faulty Equipment, it will refund to the End User the current retail sales price of the Equipment at the time the warranty claim is made by the End User.

This limited lifetime warranty (the “Warranty”) does not extend to heel straps provided with the Equipment, if any, or to any damage to Equipment caused by inappropriate or unauthorized use, maintenance, repair, nor any alteration, abuse or neglect by the End User. Except for new and unused Equipment, cosmetic damage, such as surface scrapes, scuffs and discoloration are not covered under this limited lifetime warranty.

This Warranty is extended only to the End User for the Equipment purchased from an authorized TrueFin retailer or seller and only covers the repair, replacement or refund for faulty Equipment. TrueFin will not be liable for any loss, injury, special or consequential damages, or direct or indirect damages to any person, entity, or property due to a fault or defect in the Equipment, including lost profits damages.

This Warranty is in lieu of all other warranties. Except as stated herein, The implied warranties of merchantability and fitness for a particular purpose and all other warranties, express or implied, are excluded from this warranty. This Limited LIFETIME Warranty states the sole and exclusive remedy available TO END USER from TrueFin, namely repair, replacement or refund, at TrueFin’s sole discretion.

Any claims made pursuant to this Warranty must be in writing and shall be either sent by email transmission, or mailed by certified mail, return receipt requested, postage prepaid, and addressed to TrueFin, LLC at: 19363 Willamette Drive #508, West Linn, Oregon USA 97068. All claims shall be deemed to be given on the earlier of the date the email transmission was transmitted and receipt confirmed, or the expiration of the second day after the date of certification of mailing.

California Prop 65 Warning:

⚠ WARNING: This product can expose you to chemicals including lead and lead compounds and/or Bisphenol A(BPAs), which are known to the State of California to cause cancer and birth defects or other reproductive harm.  For more information go to www.P65Warnings.ca.gov.

Products Liability Warnings:

⚠  WARNING: CHOKING HAZARD – SMALL PARTS. Not for children under three (3) years of age.

⚠ WARNING: THIS IS NOT A LIFE SAVING DEVICE. Do not leave children unattended while device is in use.

TRUEFIN

Mailing address: Truefin, PO Box 645, West Linn, Oregon 97068

Shipping address: Truefin, 19363 Willamette Drive # 508, West Linn, Oregon 97068