William Trubridge and I had discussed reviewing the new Vertical Blue Blackfin. He had my address, but I didn’t know if he’d decided to send a pair.
So when the mailman rang my doorbell, I had no clue. I signed off, and he handed me the box. ‘Singapore,’ it said. My mind, the ever-excellent helper, began reciting things I knew about Singapore.
For example, I’d heard it was illegal to carry durian fruit on a bus there because of the smell, that durian fruit contains a lot of tryptophan – which boosts serotonin, and that the Singapore Air Force, until recently, flew an advanced version of the..er…uh…
But wait!…could it be?!
Removing the sturdy and perfectly fitted outer box, I found an elegant black sleeve with an understated logo and the words ‘The Blackfin’.
Classy.
Inside the sleeve, each fin is nested in its box, supporting the radical blade angle and protecting against scratches or impacts.
The entire packaging experience is perfectly balanced in form, function, and aesthetics – a suitable prelude to the fins’ emergence.
Check out this enthusiastic un-packaging video from @depthmetal on Instagram (Make sure your sound is on for the full effect!)
The fins are beautiful, with flawless craftsmanship and an elegant, understated design. They’re also incredibly light (possibly due to the relativistic effects of Dark Matter woven into the blade fiber matrix – just kidding).
Based on my foot length, I was sent size 10 US foot pockets, which are a full size smaller than I usually wear.
With some trepidation, I slipped my foot, cotton sock and all, into one of them. Surprisingly, there was a little play—enough for a 3mm sock and maybe enough that without a sock, they could slip off in a hard sprint.
To The Pool
I carefully slid the fins into my ancient fin bag (I couldn’t help but notice that with the fins in it, the bag seemed oddly lighter) and took them to the local YMCA pool. I work out there almost daily with my monofin.
Both monofins and breath-holds are banned, but I’ve been granted an exception provided I do my best to surface at intervals reasonably close to the lifeguards’ required 15-second pool scans.
I worried about overpowering these very soft bifins trying to sustain such a brisk pace.
First Pool Session
The fins (without socks) slipped on easily, evoking my fear of the pockets coming off under load. Will Trubridge boldly claims that these are “the world’s most comfortable footpockets.”
Brave words—we’ll see.
After working out all winter with my monofin, I felt pretty discombobulated, switching to bifins. Slightly bow-legged and with flexible ankles, I’ve always had to focus on not having fins knock into each other. While improving rapidly, my technique was lousy, and the 25-yard swims were slow and laborious – reinforcing my concern about the pace with these soft blades.
Regardless, I came out of that first session with four positive observations:
- I need to work on technique.
- The fins would not collide unless I made a conscious effort and forced them to.
- I could not overpower them.
- They are pretty forgiving of lousy technique.
- What footpockets? Seriously. I completely forgot about the footpockets. ‘Bunny slippers,’ I thought, ‘They’re comfy as bunny slippers.’
Second Pool Session
I experienced an immediate improvement. I matched my typical ‘brisk cruise’ times in a monofin with uncanny exactitude, albeit somewhat longer recoveries.
‘Hmmm…’ I thought, ‘This is getting interesting’…
Third pool Session
I took more brisk cruises and hard sprints to stay within the time envelope. Recoveries were a little quicker as I grew accustomed to the fins and began to relax. I shaved a couple of seconds off my times and played around with acceleration and treading water to get an idea of how the fins might do coming up from depth.
One of the things I like least about every other pair of fins I’ve used is that ‘Are we there yet?’ feeling coming up from depth in full winter kit. A winter open water session would allow me to check out the Blackfin’s vertical performance with the more extreme changes in buoyancy engendered by thicker winter suits and weights.
Open Water
It’s been a really strange winter. There were a couple of days in February when daytime temps approached 70f/21c, dropping down to 15f/9c at night. This change was so abrupt that it filled the night sky with latticeworks of lightning, rolling thunder, and snow.
The first open-water day for the Blackfin was edging toward 50f/10c. Resting on the surface, I could feel the sun on my back, the infusion of warmth not quite offsetting the slow loss of body heat into stunningly clear 36f/2.2c water.
Surface Swim
These fins are a joy on the surface. They stay in the water on the backstroke and cover a deceptive amount of distance with minimal effort. I swam about a kilometer on the surface and could switch from surface cruise into pre-dive relaxation mode with very short recoveries.
Down and Up
At a grand total of 600 grams, the Blackfins do not contribute much weight when you swing them up out of the water for a duck dive. However, once in the water, things change. They easily overcame the substantial buoyancy of my winter suit. I hit the glide phase (negative buoyancy) surprisingly soon and let myself fall until I felt heavy enough to get a good idea of how the fins would feel coming off the bottom.
This is where almost every bi-fin I’ve ever used left me wanting more power. At depth, the suit was far less buoyant, and I could really feel the 11 lbs/5 kg of weights I was wearing. Strangely, as I launched off the bottom, I forgot about how the fins were performing and found myself enjoying the lighting, looking for fish, and checking to see where my dive buddy/photographer was.
Forgetting about them is a theme with these fins. Instead of feeling like I was working hard and getting nowhere, I felt I was covering way more distance than my efforts deserved.
On the Vertical Blue Shop, William makes the following claim:
The Blackfin provides consistent power, perfectly balanced between both phases (forwards and backwards) of the fin stroke. This means the legs work continuously, but at a lesser force compared to most other fins, where the force required fluctuates up and down.
The effect is that an ascent seems like it’s chopped in half: after a short period of fin cycles you’re already hitting the surface wondering where the depth went! It’s only when you look at your gauge afterwards and realize that those leisurely fin strokes were actually getting you 1.1–1.3m/s that you discover what happened!
Compared to other fins it feels like cheating.”
He’s right. Despite my imperfect technique, the Vertical Blue Blackfins translated minimal effort into outstanding performance.
It was during a series of heat-generating sprints on the way that I felt like I hit my stride with these fins. The bottom blurred by so fast I couldn’t focus on it, and I surfaced well beyond expectation.
Conclusion
The Vertical Blue Blackfins performed superbly in all open water and pool freediving phases. They are far and away the best-performing bifins I’ve ever encountered.
Every other pair I’ve tried—plastic, fiberglass, or carbon fiber—had a ‘sweet spot’ – a range, sometimes large, sometimes small, where the fin’s performance was at its best. With these, the ‘sweet spot’ is everywhere. I never felt a less-than-solid return on my effort across a full range of frequencies, amplitudes, and power.
The fins do not side slip, brush against each other, or ‘bottom out’ under load. At the same time, they are responsive to even the softest input and wonderfully symmetrical in power during both up and downstroke. I could not overpower them in a hard sprint or ascending heavily weighted from depth. And, no matter how much force I applied, the foot pockets were completely comfortable and secure.
A Cautionary Note on Carbon Fiber
These fins are made with Carbon Fiber, the best-performing and most fragile fin material. The durability of such fins depends very much on the quality of craftsmanship, and these fins are very well made. Treat them with respect, and they’ll be there for you for a long time. Throw them in the bottom of the boat and step on them, and you might have a bad day.
Key Features
- 3D-Dive® – the first fin to use this patented technology, which uses a gradient of 27–30º in inclination between the inside and outside of the blade to prevent external rotation
- Asymmetrical anterior edge to avoid fin contact
- Featherlight carbon fiber for a weight of just 300g per blade
- Seac foot pockets, adjusted in the factory for high-performance
Price
- Blackfin Freediving Fins: $645 USD / €591 EUR / £508 GBP
Buy Now
Vertical Blue Blackfin Freediving Fins
Introducing the Vertical Blue Blackfin. Designed according to the stringent specifications of Team Vertical Blue, these are the most precisely engineered blades on the market
