Filleting knives for sea kayakers

A good filleting knife is essential for the fisherman who likes to bring home his catch to eat.  While you can always bake smaller fish whole in the oven, or even steam them if you have a big enough fish kettle, to make the most of big fish you need to be able to fillet them.  Filleting fish is not difficult (I love watching a professional make it look easy!), but it can be difficult if you don't have a decent knife. 

I don't fillet fish while kayaking, at the most I just head and gut them.  However, being the stingy type I liked to have just one knife to do the job of gutting the fish on the yak and filleting them when I got home.  The knife I have used for many years is one of several variants made by Marttiini of Finland.  Marttiini make a good selection of knives for fishing.  Mine (which is showing its age these days) is the classic type that comes with a leather sheath:

Nicely made sheath but not practical on a sea kayak.  Once the sea gets it wet, it stays wet for days.

The blades are great on Marttiini knives, but the handles seem to have been made for midgets.

I have no real complaints about the knife, other than the fact that leather sheaths are hopeless at keeping a knife dry and rust free, particularly in tough salt water conditions.  The steel of my Marttiini knife is excellent at keeping an edge, which means although its purportedly stainless, it contains a higher proportion of carbon than most stainless steel used in knives.  Unfortunately that ability to keep an edge does mean you'll occasionally have rust spots develop if the knife stays in a brine-soaked sheath overnight.

I prefer a 6 inch / 15cm blade - but an even longer blade can be handy for those big fish when you need to put the knife through the flat side of the fish's flesh to remove the fillet when cutting towards the tail.  I like a flexible blade, as I'm one of those finicky filleters who likes to cut out each rib cage bone.  A fine flexible tip is handy for doing this, but a lot of professionals use stiff filleting knives and there must be a reason for their preference! The other occasion a flexible blade is handy is when filleting a flat fish, as this very short clip shows:

However, as I mentioned the problem with the Marttiini knife is its leather sheath, which can take days to dry out after a fishing trip.  Meaning the knife has to kick around without its sheath during that time which is an annoyance.  So this year I started looking for an alternative.  My fishing buddy uses a Rapala filleting knife in a plastic sheath, and I was hoping this was the answer to my problems.  Unfortunately he says once the salt gets inside his sheath, it's hard to rinse it all out and the sheath stays damp on the inside too.  I was disappointed to hear this - as I had my heart set on on one of Marttiini's new Martef coated knives in a plastic sheath, which might prove completely rust resistant but I can't help thinking that the same issues will eventually raise their head again.

But I recently came across what might be a nice solution to my salt problems.  While on holiday in France with the family, I came to appreciate an old knife of my wife's made by the French company Opinel.  These knives are cheap and effective, and the quality of the steel is excellent, even in the case of the stainless versions.  It occurred to my that these knives have no need of sheath, as they fold.  They lock both open and closed, so they're safe to use.  And given their price, if they fall overboard, no problem.  So when got back I looked them up to see what models they made, and to my delight I discovered they make a folding filleting knife.  I promptly ordered the 12cm version:

This really is a very slim, compact knife.  It'll fit most pockets no problem.

A long, delicate blade.  Great for filleting, maybe not so good for any heavy work.

It's a nice knife, perhaps the blade is just a little too flexible and thin to my taste - sometimes you have to cut through some fairly hefty cod bones - I'd prefer a little more backbone to it.  But the handle fits brilliantly into your hand - something that always annoyed me with the Marttiini, as the shots below show.

This knife feels perfect in the hand.  Top marks for the handle.

You can really see the how the extra length and slimness of the Opinel handle makes for a much more comfortable knife to hold.

When compared to the Marttiini, you can see how the knives share a similar overall length, but the Opinel has a much nicer handle, it really feels good to hold.  I can't vouch for the quality of the steel in terms of how long it will keep its edge and frankly I don't expect it to match the Marttiini, which after all is on the edge of what can still legitimately be called stainless.  But I wasn't impressed to see that Opinel had not only mirror buffed the blade but had varnished it on top - why do they do this?  It's supposed to be a working knife - not something that sits in a drawer for formal occasions!  Or perhaps it isn't, in which case I'll have bought the wrong knife!  But as far as I'm concerned it ticks quite a few boxes for my filleting / fish gutting requirements when sea kayak fishing: it's easy to rinse so it won't retain salt water, there's no sheath to have to dry out before storing the knife and it folds to a small compact size that fits very neatly into my tackle box. 

Marttiini knives have always had locks to keep them open, but they now also feature a guard that keeps the knife from opening.  Nice feature, and in keeping with the simplicity of Opinel design.

As with all my product reviews, I'll be posting an update after several months to let you know how the knife is standing up to the abuse it's bound to get.  :-)