Lake O Fishing Tips

While Lake Otamangakau might be considered small by most lake standards it’s extremely diverse in terms of terrain, food supply, and trout behaviour. This can be a bit intimidating at first if you haven’t spent much time out there, as it's tough to know where to start and what to try in the varying conditions you’re likely to be faced with.

This article is intended to provide anglers with an overview of the most commonly used, and most successful, techniques for catching Lake O trout. Some of these techniques will already be a little bit familiar to anglers so hopefully it helps you either sharpen up your tactics and tools, or provides inspiration to try a new technique this season.

Kyle Adams Fly Fishing NZ


  1. Stripping Teams Of Three Flies
  2. Damselfly Tactics
  3. Plonking
  4. Shallow Water Trout Hunting
  5. Static Nymphing

We’ll focus on boat based fisherman here but the same tactics can be applied to shore based fly fishing at Lake O too, such as dry & dropper in the shallows, or plonking in the canals.

When it comes to fly fishing gear for Lake Otamangakau, it is an extremely accessible fishery and for the most part your same go-to 9’ #6 fly rod and floating line will see you fishing all of these techniques. If you’re planning on really getting into it, then a 10’ #6 rod and reel and spool set loaded with a floating line, a fast intermediate line and 3ips sinking line is the go to specialist kit and will see you covered for most NZ stillwater situations.

No matter how you skin it, there are a number ways to successfully catch fish fly fishing on Lake O. However, the techniques listed below would be the commonly used, and consistently the most successful techniques used on the lake.

Let’s get into it…


Stripping flies can be performed with up to three flies set up on a 13ft leader and this is a great way to cover a lot of water. Using three flies works by grabbing the attention of a passing fish, along with providing more exposure to the flies making them more likely to be intercepted by the trout as that cruise around, swimming in all different directions and weaving in and out of the weed. 

Fly line choice is based on the depth of water you intend to fish along with your given drift speed. So, if you are drifting the deeper channels then an Airflo Sixth Sense Di3 or Di5 would be suitable, however if you choose to fish outside of the channels then the fly line required will be anything from a floating line like the Airflo SuperFlo Power Taper or a 1.5ips sinking line like the Airflo Clear Camo Intermediate. I feel this is the ultimate allrounder line for the shallower water that is typically 4ft to 8ft deep.


An erratic fast retrieve with good pauses in the mix is a great way to go about it. Once you have made a cast, allowing the fly line to sink and reach the desired depth. This depends entirely on the type of water fished, sink rate of the fly line, and the speed of which the boat is drifting.

If you’re fishing from a drifting boat then drift chute is a must have item to achieve the required and consistent drift speeds. This keeps you in the fishing zone longer and the wind blows strong often too, so the use of a drift chute becomes a critical tool.

The wind is naturally behind you while drifting from a boat with a drift chute out, so the key here is to predict what direction the wind is blowing from and set up your drift accordingly. Position the boat to allow the best possible drift down the chosen path of water, and consistently achieving a long and controlled drift in the water most suited the to your fly line sink rate is the goal.

Alternatively, fishing from an anchored boat is a great way to search out the deeper water of the lake’s channels between the defined weed beds which trout frequent. A medium to fast sinking line is required here, sink rates of 3ips or 5ips will cover most bases using the same set up and retrieve as described above.

Just remember, after the cast has been made the flies will need to be left to sink a bit longer to reach the bottom before retrieving because we’re no longer moving with the current.


A 13ft leader using 8lb-10lb fluorocarbon tippet is ideal. The difference is we’ll be fishing a team of three flies that are spaced out with. The top and middle dropper flies are attached via the tag created from a Surgeon’s knot, while the point fly is attached to the end of leader using a Lefty’s Loop knot which gives better movement to the fly, I recommend this knot for all three flies.


A team of three woolly buggers is hard to go past. Alternatively, substituting the top dropper with a bold or brightly coloured fly or boobie pattern will often work well to grab the attention of passing fish by luring them into inspect the team of flies which often results in an eat from one of the offerings. The fly patterns recommended below are suggestive patterns that provide important, life like movement in the water, which can represent several food sources found in the lake such as small fish patterns, tad poles, leeches, and dragon or damselfly nymphs.   


Belinda's Bitch Slap

Belinda’s Bitch Slap in Olive/Orange

Balanced Leech in Black Magic

FOB Olive Woolly Bugger


Little Bugger Brown & Peacock

Little Bugger in Brown & Peacock

Damsel Bugger


FAB Fire

F.A.B in Fire

Little Bugger in Olive & Peacock

Perky Booby in Peach

Trophy Rainbow Trout From Lake Otamangakau


Fishing from an anchored boat during a damselfly hatch is a fun and exciting way to target fish. You can be covered in them. Occasionally fish will breach and then there’s no question about what the fish are eating. It’s a good size nymph meal and Lake O fish will gorge themselves on them.

A floating line works well in general, however a fast intermediate comes into its own by being able to fish a little bit deeper, but also enabling greater contact with the flies during a choppy or rough lake surface by staying below the surface disturbances.


By anchoring the boat behind a weed bed this allows the flies to be positioned over the edge and then fished effectively back and up to the weed bank. This proves to be a productive and super exciting way to catch fish during the height of a damsel fly hatch as the vulnerable nymphs in great numbers swim up to the weed edges to hatch.

A slow as you dare retrieve works well here to emulate the natural nymph swimming; however a faster varied retrieve is also effective. Either way, staying in contact is key as the takes can be subtle.


14ft of 7lb or 8lb fluorocarbon leader will suffice.  Attach your flies using a Lefty’s Loop knot which is recommended for greater movement of the fly.

If you choose to fish two damselfly nymphs, then either attach the second fly as a dropper via a Surgeon’s Tag or, alternatively tie to the curve of hook.


Ultra Damsel Nymph

Ultra Damsel Nymph

Swimming Damsel

Rob's Redhead Damsel

Dodger Damsel

Andrew Harding On Lake Otamangakau


This would have to be the most successful and reliable technique used on the lake, which can be deadly effective at times. Plonking is a style of indicator nymphing from a drifting boat which isn’t too dissimilar from the classic Taupo river nymphing style.

This is a great way to cover most aspects of the lake using a floating line from the moderate depths of the channels, pockets of water between the patchy weed and the shallow margins of the lake edge.

The same Lake Otamangakau rules apply with the best fishing during conditions with a broken, choppy, or rough lake. Presenting the flies naturally, as they bob around suspended under an indicator or dry fly indicator at the chosen depth, this proves to be very appealing to fish that are seemingly totally unaware of your presence as the boat quietly drifts along the lake.

Targeting the deeper pockets of water between the weed is also an effective and fun way to fish from a drifting boat. With a pair of polarised sunglasses, the pockets of water can be searched out and targeted whilst drifting, trout frequent these waters and are often seen breaking the water surface as they feed on the available food.


As always, the wind will be behind you so cast ahead of the boat at a comfortable range, but not so far that you lose contact with your flies. Allow some time for your flies to sink, remembering to keep in contact throughout this phase. After the cast is made, make sure you are ready as fish can pounce on the fly as soon as it makes the plonk from landing on the water.

The retrieve is influenced by your drift speed, so you’ll need to speed up or slow down depending on what the wind is doing. Keep in mind that the goal here is to stay in touch with the flies throughout the drift by retrieving the slack line that forms as you drift closer to the indicator and leaving them to naturally bob around in the water.

That said introducing movement into the flies from time to time with short strips will also lure fish into eating the fly.


As always, a 13-14ft leader with 7lb or 8lb fluorocarbon is the way to go. My indicator preference is a treated poly yarn like the Loon Strike 2, attached via a small piece of plastic tube. Utilising an adjustable indicator is key here, this allows easy adjustment and re-positioning of the indicator to suit the frequently changing water depths. Alternatively, a highly visible and buoyant dry fly also works well and quite often accounts for more than a few fish.

This is generally a two fly rig, consisting of a weighted bead head fly on point to sink the flies, along with a unweighted dropper fly above, attached above via the tag of a Surgeon’s knot. Having two flies positioned apart means that different depths or columns of water can be covered at the same time.

As an example, the deeper channels of the lakes require a greater distance from the indicator to the flies, say a rod length away, however other parts of the lake will only require the indicator to be only a few feet from the flies.

The goal here is to have the flies suspended near the bottom, but not right on the bottom or constantly becoming fouled in the weed.



Hot Snail

Hot Snail 


Diving Damsel


Rob's Redhead Bloodworm

Rob's Redhead Bloodworm

Swimming Damsel

Crystal Chironomid 

Tarny Warny On Lake O


The lakes shallows are happy hunting grounds for trout which frequent these waters feeding amongst the weed, mud, and sand flats, and often tailing in less than a foot of water. A floating line with a dry & dropper rig is well suited to this type of water depth and covers it well when drifting the shallows and margins of the lake.


Due to the shallow nature of the water fish can be spotted cruising relatively easy in favourable conditions, so it pays to keep an eye out and be ready to make a cast if the opportunity arises.

Choose a dry fly to best suit the lake conditions, it is crucial that the dry fly is easily seen. If it is hard to see due to glare or chop on the lakes surface then increase the fly size and go to a brighter more easily seen colour. Fish can intercept either of your offerings, however, it is fair to say that the nymph will likely receive the most attention.


Start with a 14ft leader of 7lb or 8lb fluorocarbon and make the dropper length suit your water depth. The dropper fly can be attached by a Surgeon’s dropper tag or alternatively tied to the curve of the dry fly hook.



Wayne's Blowfly

Wayne’s Blowfly

PMX Hi Vis

Kiwi Cicada


Crystal Chironomid Tan

Crystal Chironomid Tan

Soft Hackle Pheasant Tail

Flash Back Pheasant Tail


This is a great way to target a specific piece of fishy water like the deep holes amongst the weeds, and also fishing over the weed beds into the deeper water of the channels. Trout frequent these areas and during a hatch of insects like damsel fly nymphs, trout really key into the weed margins making an easy meal of the vulnerable and available nymphs.

Commonly, boats are positioned either on top of or behind a defined weed bed and down the line or edge of a weed bed. This is a stealthy approach, and an effective way to fish that requires little effort, but demands a lot of concentration, making sure to watch the indicator intently and not miss a strike when it dips under. Blink and you'll miss it.


Much like plonking, the cast is made down wind and positioned out in front of the boat and at a comfortable length, and left there to sit for as long as you wish. After a period the flies can be brought closer to the boat by retrieving them slowly and intermittently as this can also produce a take.

Additionally, during the hight of terrestrial activity during summer the strike indicator can be happily substituted with a buoyant dry fly pattern. At this time of year lots of insects will end up on the lake’s surface, which are typically blown in by the wind from the surrounding vegetation. Beetles and Cicadas are an easy meal for the passing trout, so it’s worth having an offering of these combined with a nymph underneath.


Refer the set ups for “plonking” as this is much the same, albeit from a stationary boat.





Flat Back Cicada

Hippie Stomper


Rob's Redhead Midge

Rob's Redhead Midge

Hot Snail

Bead Head Pheasant Tail

So there you have it, the most common methods of fly fishing on Lake Otamangakau and plenty of options for you to try the next time you’re out on the Big O. Anglers are creatures of habit and we have a tendency towards recency bias i.e. I’ll stick with what caught me fish last time.

Lake Otamangakau is its own beast however and when it’s slow going it can really pay dividends to switch up your mindset and play around with a few different techniques.

It’s easy to have a few rods rigged up and be ready to switch over when one isn’t working, or you see activity or the changes throughout the day so get set up and ready to roll for whatever Lake O is going to throw your way.