Photos: Okuma · supplied retailer imagery
Carp reels · Big pit reels · Our take
Okuma Obsidian
OSD12000-35AY
The Okuma Obsidian OSD12000-35AY packs a big spool, long-cast features and a carbon build into a surprisingly light package. Here’s where it fits on the bank.
- OSD12000-35AY model with a 4.3:1 gear ratio and 18kg maximum drag.
- C-40X carbon frame and side plates, with a C-40X Cyclonic Flow rotor.
- 35mm stroke with super-slow oscillation for tidy line lay and distance casting.
- Supplied with a spare spool and two spool reducers for different line capacities.
Make sure it’s the right one. This review covers the Okuma Obsidian OSD12000-35AY, the lightweight C-40X carbon carp reel with a 35mm spool stroke.
Tackle Index Score
Tackle Index score
A lightweight, distance-focused carp reel with a strong feature set and useful spool flexibility.
Desk-research score from specs, price and fishing fit · How we score
- Product Quality9/10
- Performance9.1/10
- Impact on Fish Catching8.6/10
- Ease of Use8.8/10
- Value for Money8.6/10
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Who it suits
Is it right for you?
Great for
- Long-range carp anglers. The deep spool, 35mm stroke and super-slow oscillation are aimed squarely at getting line out smoothly and laying it neatly.
- Anglers building a lightweight set of rods. At 520g, it helps keep the whole outfit feeling lively instead of making every rod feel like a lump of scaffolding.
Maybe skip if
- Short-range or small-water carp anglers. The huge spool and long-range design can be a bit much when you’re fishing under your feet or just across a canal.
- Anglers who prefer a traditional heavy-duty reel feel. The carbon construction saves weight, but it won’t have the same solid, dense sensation as some metal-bodied alternatives.
The lowdown
Introducing the Okuma Obsidian
The Okuma Obsidian OSD12000-35AY packs a big spool, long-cast features and a carbon build into a surprisingly light package. Here’s where it fits on the bank.
- OSD12000-35AY model with a 4.3:1 gear ratio and 18kg maximum drag.
- C-40X carbon frame and side plates, with a C-40X Cyclonic Flow rotor.
- 35mm stroke with super-slow oscillation for tidy line lay and distance casting.
- Supplied with a spare spool and two spool reducers for different line capacities.
Quick verdict
Verdict
The Okuma Obsidian is a cracking choice if you want big-pit capacity without lugging a brick around. Its 520g weight, super-slow oscillation and long-distance-friendly spool give it a very clear job on the carp bank.
It’s not the cheapest sort of reel you’ll find, and the huge line capacity will be overkill for plenty of venues. But for long-range work, big pits and anglers who value a light setup, this looks properly well sorted.
A lightweight, distance-focused carp reel with a strong feature set and useful spool flexibility.
Desk-research score from specs, price and fishing fit · How we score
- Product Quality
- 9/10
- Performance
- 9.1/10
- Impact on Fish Catching
- 8.6/10
- Ease of Use
- 8.8/10
- Value for Money
- 8.6/10
The carbon construction, one-piece bail, carbon drag and lightweight aluminium shaft give it a well-considered premium feel.
The deep spool, 35mm stroke, super-slow oscillation and 4.3:1 gearing are well matched to long-range carp fishing.
It won’t find the fish for you, but tidy line lay, controlled drag and a lighter setup can make distance fishing more consistent.
The spare spool and reducers add flexibility, though the large capacity means you need to choose your setup carefully.
It offers a lot of specialist carp-reel features, with the best value showing when you genuinely need long-range capacity and low weight.
Head to head
How it stacks up
Side by side with the closest kit we've reviewed. This updates as we add more reviews.
Okuma
Okuma Obsidian (this one)
Top scorer
Top scorer
Scores are our own, out of 10. Best in each row is in green. Prices change, so check the latest before you buy.
The full rundown
Everything you'll want to know about the Okuma Obsidian
Big-pit carp reels can sometimes feel like you’ve bolted a small winch to your rod. Loads of capacity, loads of metal and enough weight to make a three-rod setup feel like hard graft before you’ve even found the spot. The Okuma Obsidian takes a different route. It’s a proper long-range reel, but the C-40X carbon build keeps the weight down to a rather tasty 520g.
That’s the headline here, really. The Obsidian OSD12000-35AY is built for anglers who want distance-friendly performance without ending up with a massive, clunky outfit. You still get a deep spool, 35mm stroke and super-slow oscillation, but the reel should feel more lively in your hands. Dead handy when you’re clipped up, feeling for the drop and trying to keep everything controlled.
The C-40X carbon frame and side plates are the main reason this reel can stay so light. The rotor uses C-40X Cyclonic Flow construction as well, while the shaft is made from lightweight A7075 aluminium. That’s a smart collection of weight-saving choices for a reel designed to sit on a carp rod for hours on end. Less heft doesn’t magically catch fish, of course, but it can make a balanced setup much nicer to live with.
At the business end, the 4.3:1 gear ratio gives the Obsidian a sensible balance between winding power and line pick-up. It’s not trying to be a frantic feeder reel. This is a carp reel for getting a bait out, settling the line and having enough grunt when a lump decides to head for the snags. The maximum drag is listed at 18kg, with a carbon-fibre drag system for controlled pressure when things get a bit lively.
The spool is where the long-range credentials really show. Capacities run from 0.33mm/680m through 0.35mm/600m to 0.38mm/500m. That’s loads of line. More than you’ll need on many day-ticket lakes, if we’re being honest, but useful on huge waters where a big chuck, wind, weed or a long underwater bar can eat up plenty of main line. You’ve got room to set up sensibly rather than scraping the bottom of the spool.
The super-slow oscillation is another proper bank-friendly feature. As the spool moves up and down, it lays line in a neat, even pattern. That matters when you’re trying to get a smooth release during a punchy cast. Fill the spool correctly, avoid leaving it underfilled and keep your line tidy, and this style of oscillation can help the reel feel more refined when you’re fishing at distance.
You’re not locked into that enormous capacity, either. Okuma includes a spare spool and two spool reducers, allowing the reel to be adapted to capacities listed as 8000 or 1500. That gives you a bit of breathing room for different waters and line choices. One spool can be set up for a proper big-water mission, while another can be made more sensible for a closer-range approach. Less faff than buying another complete set of reels.
The one-piece bail and ultra-light screw-in handle keep the design clean and practical. The 8+1 bearing setup should give the winding gear a smooth feel, while the aluminium shaft helps keep the overall outfit from becoming too hefty. This isn’t a reel aimed at margin stalking or tiny commercial pools, where its capacity would be a bit daft. It makes most sense on open water, long swims and venues where every extra yard can change the bite-time.
There are a couple of things to think about before you part with your quid. Carbon construction is a big part of the appeal, but anglers who like a reel to feel dense and indestructible may prefer a more traditional metal-bodied design. Also, a deep spool can encourage people to overfill or carry far more line than necessary. Use the reducers when appropriate, balance the reel to your rod and the Obsidian starts to look like a cracking bit of kit rather than overkill.
Specifications
The nuts and bolts
- Model
- OSD12000-35AY
- Gear ratio
- 4.3:1
- Weight
- 520g
- Maximum drag
- 18kg
- Bearings
- 8+1
- Line capacity
- 0.33mm/680m, 0.35mm/600m, 0.38mm/500m
Specs checked with Okuma, Oct 2026.
Spot a model or spec change?
Our take
The angle
This is all about cutting weight without making the reel feel like a toy. The C-40X carbon frame and side plates, lightweight aluminium shaft and screw-in handle keep the Obsidian nimble, while the 35mm stroke and deep spool give it the long-range credentials.
The spare spool and two reducers make it more flexible than a standard big-pit reel, too. You can set it up for heavier distance fishing or tame the capacity for more normal carp work, rather than carrying different reels for every swim.
What you’re buying
A light reel with big-water intent
The Obsidian OSD12000-35AY is a large-capacity carp reel built around a C-40X carbon frame and side plates. Its 520g weight is the eye-catcher, especially when you’re putting together three rods and don’t fancy carrying a bag of bricks down the track. The C-40X Cyclonic Flow rotor, A7075 aluminium shaft and screw-in handle all follow the same lightweight thinking.
The 35mm stroke and super-slow oscillation are aimed at clean line lay and smooth distance casting. A 4.3:1 ratio gives it a useful carp-fishing balance, while the 18kg carbon-fibre drag offers plenty of control when a fish turns nasty near weed or snags. The one-piece bail keeps the front end simple and tidy.
Worth knowing. The standard line capacity is huge: 0.33mm/680m, 0.35mm/600m or 0.38mm/500m. That’s excellent for big pits, but don’t feel you have to fish all that capacity on a small or medium water. The included reducers are there for a reason.
On the bank
Best when distance and weight both matter
This reel will suit the angler fishing a large reservoir, gravel pit or open lake where the far margin, island or plate is the target. The deep spool gives you plenty of line to work with, and the super-slow oscillation should help create a tidy line lay for repeatable casting. Keep the spool filled properly and match it to a rod that can load the reel without feeling unbalanced.
It also makes sense if you’re building a lightweight setup. A 520g reel won’t turn a balanced carp rod into a featherweight wand, but it can make long sessions more comfortable. The spare spool is handy for a different line choice, while the reducers let you tone down the capacity when the swim doesn’t call for a full-on big-pit arrangement.
For close-range margin work, you’re unlikely to get the full benefit. The reel will still do the job, but its long-range spool and big capacity are a bit like taking a tow bar to the corner shop. Fine, just not the most sensible tool for the job.
Quick answers
The bits anglers usually want to know
Is it a proper distance reel? Yes. The 35mm stroke, deep spool and super-slow oscillation all point towards long-range carp fishing. That doesn’t replace good casting technique, correct spool filling or a well-matched rod, but the reel’s layout is designed to support that style of fishing.
Is 18kg of drag enough? For UK carp fishing, it gives you plenty of headroom. The important bit is using the drag smoothly and sensibly, especially close to snags. Maximum drag figures don’t mean you should simply lock everything solid and hang on.
What do the spare spool and reducers add? They make the Obsidian more versatile. The spare spool lets you carry a second setup, while the two reducers reduce the working capacity to 8000 or 1500. That’s useful when you move between a big-water campaign and a more modest venue.
Worth knowing. Think about the venue before choosing your line and spool setup. On a massive pit, the deep spool is bob on. On a smaller lake, a reducer can save line, reduce unnecessary bulk and give you a more sensible setup for the swim.
On paper
Pros & cons
What we like
- Very light at 520g for a large-capacity carp reel.
- Deep spool and 35mm super-slow oscillation suit distance casting.
- 18kg carbon-fibre drag gives plenty of control over proper lumps.
- Spare spool and reducers add useful versatility.
Worth knowing
- The large capacity is more than you need on many smaller waters.
- Carbon construction may not appeal if you prefer the dense, bombproof feel of a traditional metal-bodied reel.
- The reel’s strengths are most obvious at range, so it may be unnecessary for short-range margin work.
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Your questions answered
What anglers want to know
The stuff you’d ask your mate on the next peg. Straight answers, no waffle.
01Is the Okuma Obsidian suitable for long-range carp fishing?
Is the Okuma Obsidian suitable for long-range carp fishing?
Yes. The deep spool, 35mm stroke and super-slow oscillation are all useful for distance work. Match it with a properly balanced rod, suitable main line and a sensible shock-leader setup, then keep the spool filled correctly for smooth casting.
02How much line does the Okuma Obsidian hold?
How much line does the Okuma Obsidian hold?
The stated capacities are 0.33mm/680m, 0.35mm/600m and 0.38mm/500m. That’s a serious amount of line, especially for UK carp fishing, but the supplied reducers let you bring the capacity down for less extreme situations.
03Does the Okuma Obsidian come with a spare spool?
Does the Okuma Obsidian come with a spare spool?
Yes. A spare spool is included, along with two spool reducers. The reducers allow the reel to be set up for reduced capacities listed as 8000 or 1500, giving you more options across different venues and line choices.
What anglers say
The word from the bank
Our read: verdict. The strongest reasons to choose it are very light at 520g for a large-capacity carp reel. and deep spool and 35mm super-slow oscillation suit distance casting.; the main trade-off is the large capacity is more than you need on many smaller waters..
Our take on the feedback
Why it appeals
Checked Sept '26 — “Very light at 520g for a large-capacity carp reel.”
Best fit
Checked Sept '26 — “Long-range carp anglers: The deep spool, 35mm stroke and super-slow oscillation are aimed squarely at getting line out smoothly and laying it neatly.”
Worth knowing
Checked Sept '26 — “The large capacity is more than you need on many smaller waters.”
Tackle Index’s take from the product details and fishing fit we checked. We haven’t found enough independent public feedback to call this an angler consensus yet.
Angler score
What our readers rate Okuma Obsidian
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Owner reports
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