Review of the RK4 fins from Apeks

[pisauron]

Got my white RK4 fins from Apeks this week and had a chance to dive with them. Might make a video soon.

I own RK3 medium size. And i do like them very much so i thought i might try the RK4s the same size.

So here is my review:

Size: Although they seem massive they are almost exactly the same size as my RK3.

Shoe size: The RK4 and my RK3 are both medium but the shoe size of the RK4 is a bit bigger and my shoes are wobbly just a bit.

Stiffness: They are just slightly more stiff than the RK3.

Material: The material is different, almost identical to my Tecline fins.

Design: Much changed, but under the water it feels exactly the same as my RK3. Back kick and helicopter work just the same.

Strap: Now you can adjust the nut that holds the strap. It has 2 positions. A welcome advancement to get your sizing just right.

Ankle: That is just horrible design. The ankle puller is made of stiff plastic and not foam or something soft. As usual, no hole to put your finger. Just a huge knob that is uncomfortable to use. I had pain the entire dive because of the ankle puller - bad design. When will Apeks drop this stupid thing?

Comfort: I also had pain in the upper part of the foot but that's subjective and depends on the shoes you use.

Buoyancy: Negative! Drops pretty fast down. But don't feel heavy underwater.


Summary:

This is a mediocre product that is not worth the premuim price. Stick with the RK3 - they were better.

My solution:

I Removed the ankle puller from the RK3 and put it on the RK4.


I will do a video review if anyone is interested.

 

[ScubaSamScubaStevesFather]

Video review would be cool. And yes that ankle tab looks ridiculous

 

[JonnieB]

The new design doesn't look as functional as the old and per your experience don't wear as well either. Truth be told, other than the RK3 and RK3 HDs, the rest of Apex's gear is mediocre and overpriced .

 

[Still Kicking]

In 24 years of diving with spring straps (pvc tubing over stainless springs), i have never once felt the need for anything to help me pull the spring off my heel.

People think they need something to pull on but it's not really necessary. If people like it and it doesn't get it the way, so be it. But to design it in such a way that it's uncomfortable is beyond dumb.

 

[Hippopotamus]

I just got mine a few days ago, but couldn't test them yet. The straps are too tight and to adjust them I need to use a rather uncommon sized key (5.5mm). I was hoping they could include a 50 cent stamped key with the fins, but noo...
I think the pull tabs are actually rubber, but a very hard one. This hardness combined with the embossed Apeks logo results in the straps actually hurting my ankles even trough the boot (acting sort of like a washboard on my ankle when moving). I imagine it will be less painful once I adjust the length, but still... who puts a hard, textured object in a place where it might hurt the user? They say the RK4 is designed also for recreational diving (that's why I got them) but clearly, these straps are useful only with some heavy duty boots, like a dry suit. Personally I won't be able to use them until I change the tabs. And for that I had to place an order for a special key... And order some new tabs...
The fins themselves look and feel quite nice to me, much better quality than my Avanti Quattros IMO. They weigh 1.3 kgs in L size to the Quattro's 1.1
Interestingly, the RK4s are made in Italy. So Mares, a company based in Genova, outsources their production to Bulgaria and China, and Apeks has fins made... in Genova (Technisub).
So for now, kind of a mixed bag. Will know more once I'm able to test them.

 

[pisauron]

I just got mine a few days ago, but couldn't test them yet. The straps are too tight and to adjust them I need to use a rather uncommon sized key (5.5mm). I was hoping they could include a 50 cent stamped key with the fins, but noo...
I think the pull tabs are actually rubber, but a very hard one. This hardness combined with the embossed Apeks logo results in the straps actually hurting my ankles even trough the boot (acting sort of like a washboard on my ankle when moving). I imagine it will be less painful once I adjust the length, but still... who puts a hard, textured object in a place where it might hurt the user? They say the RK4 is designed also for recreational diving (that's why I got them) but clearly, these straps are useful only with some heavy duty boots, like a dry suit. Personally I won't be able to use them until I change the tabs. And for that I had to place an order for a special key... And order some new tabs...
The fins themselves look and feel quite nice to me, much better quality than my Avanti Quattros IMO. They weigh 1.3 kgs in L size to the Quattro's 1.1
Interestingly, the RK4s are made in Italy. So Mares, a company based in Genova, outsources their production to Bulgaria and China, and Apeks has fins made... in Genova (Technisub).
So for now, kind of a mixed bag. Will know more once I'm able to test them.

Yes that pull tab is horrible. I opened the key with an adjustable wrench (2 needed).

Wait so the fins are made in Italy? Not UK?
And mares makes gear in China?

 

[Hippopotamus]

Wait so the fins are made in Italy? Not UK?
And mares makes gear in China?

Yes. The point of the 3rd photo is to show where it's made. Here it is again in more detail.
My Quattro+ are made in Bulgaria, so is my Mares Smart. I recently bought a Mares snorkel made in China. At any rate, none of their gear I got is made in Italy - while production facilities are pretty much next door...

 

[justinthedeeps]

The lightness and buoyancy of the RK3 is one of my favorite things about it, and it's the reason I switched over from huge Jetfins that sink.

Even in a thick drysuit for 7°C diving a rebreather, the RK3 can still do the job well, and makes a great travel "tech" fin too.

If I need more raw power, I bring a DPV.

It's cool that they are innovating.
Would be sad though if they stopped making a fin with the above characteristics.

 

[Umuntu]

Truth be told, other than the RK3 and RK3 HDs, the rest of Apex's gear is mediocre and overpriced .

I disagree.

Apeks make excellent regulators. The design of their 1st stage balancing mechanism is a bit different from other brands and they are very easy to service. Their 1st stage service kits are identical across their range too. They do their own manufacturing, unlike so many other brands which OEM manufacture in Taiwan or Japan and stick their logo on.

I also like their wings (especially the PSD wings), which have optional internal bungees to prevent taco-ing, built-in single tank stabilisers, and the lowest external profile valves. And if you like shoulder dump valves, the design of their shoulder dump valve is simpler, lower profile, and more reliable than the generic dump valve. All of their valve openings are compatible with generic sizes too, if that’s what you prefer.

I like their reels too, which have been widely copied.

In general, a lot of R&D, thought and design effort is evident in all their products.

You should expect to pay more for high quality products.

The popularity of their equipment with military and professional divers is an endorsement of their quality.

 

[Umuntu]

I think the pull tabs are actually rubber

Very little modern scuba equipment is made out of natural rubber these days, because of rubber’s poor aging and vulnerability to sunlight I suspect, but don’t know, that it’s a modern synthetic compound such as monprene or a silicone compound.