The former Scotland international tempted three of the five fish he landed at Stenhouse near Burntisland inside two hours on the multi-coloured pattern which was tied onto his cast at the last minute.
Now, the ex-miner and his pensioner partner Brian Abel are heading for the Grand Final of the Scierra Pairs in Llyn Brenig, recognised as one of the best top-of-the-water trout fisheries in the UK, on Sunday, August 28.
Joining them are two other members of the ABC and D Club based at Cardenden, Shaun Dickson and Shaun Halleron, who were first back at the jetty with eight fish in under two hours with Cowan and Abel returning six minutes after that.
However, the weight of fish from the Cowan/Abel pair, which topped the 20lb mark, tipped the balance with Dickson and Halleron in with over 19lb in their bag.
Cowan, who won a gold medal in his only appearance for Scotland at Bewl Water in Kent when he was aged 70, said that he parked his car at Stenhouse, got out his gear and looked in his box for suitable patterns.
The Glenrothes-based angler, who knows the water near Burntisland as he fishes it rain, hail, sleet or snow every Wednesday, picked out two flies, a blob and also a cut-throat cat's whisker and then noticed a fly on the ground.
And the 78-year-old said: "I picked it up. It was multi-coloured, like a mosaic, with black, red, touch of green and also red and it had multi-coloured eyes. I went for a cup of coffee and came back to the car and thought, why not, so I tied it on the point.
"We left the jetty and headed for the east or Kirkcaldy end of the lake and there was a gusty, chilly south-east wind blowing, not ideal for fishing. I've fished in worse, mind you, but you never know. It's what happens on the day.
"I was fishing a DSI3 sweep and the first, second, third fish I tempted went for that fly. Brian, who is my regular pairs partner, was into three and that was our quota."
The banter about the final has already started and the quartet have now to sort out who drives to Conwy in North Wales for the prestige event.
Cowan, who used to work on the coal face and the belt underground at Seafield near Kirkcaldy, said: "I've fished the Pairs final once before in Rutland and I was not placed, but you always go to win and you never know what is going to happen."
There is still an opportunity to enter the pairs event and here is the current calendar in Scotland: Eden Springs, Cupar, Saturday, March 26, full; Lake of Menteith, Saturday, April 23, full; Eden Springs, Saturday, May 21; Glencorse near Penicuik, Saturday, June 4, full; Harelaw near Neilston Glasgow, Saturday 4, June and Sunday, june 5; Black Loch near Falkirk, Sunday, June 19; Glencorse, Sunday, August 7, full.
Meanwhile, Allandale Tarn (open 9am to 4.30pm, closed Tuesday) and Bangour (opening times, 8.30am to 5pm, closed Monday) have re-opened and Glencorse re-opens today (March 19). Owner Bill Taylor has carried out remedial work to boats and paths and he reminds anglers that he is boat fishing only and there is no bank fishing. Anglers
He also asks fishermen to park as close to the wall and the
car in front as possible and only
in the designated bays and he added: "Don't park in the passing bays or beyond the entry gate."
Meanwhile, a roadshow visits Edinburgh during its UK tour to get the nation excited about the sport of fishing and the upcoming Sea Angling Classic competition from June 15 to 19 June in Portsmouth.
A boat and trailer is the top prize during the festival and, in Edinburgh, there will a be a chance to meet expert anglers to find out the best bait, rods, reels to use.
Event partners include Penn, Rapala and Okuma and Wetwheels who provide fishing opportunities for disabled people on specially adapted boats.
Fishing electronics specialist Lowrance® will be there providing advice and giving free software updates to owners who already have their units.
Classic founder Ross Honey said: "We're looking to help inspire young and old anglers and attract new ones." Local dates are Thursday, March 24: Glasgow Angling Centre, 1 The Point Retail Park, 29 Saracen Street, Glasgow: 15.00 to 20.00 and Friday 25 March: Edinburgh Angling Centre, Unit E, Granton Retail Park, 65 West Harbour Road, Granton, Edinburgh: 15.00 to 20.00
The Sea Angling Classic is a catch, photograph, and release format, focusing on five species, tope, smooth hound, rays, bass and black bream.
Coarse fishing now and Roz Cassidy, a member of the Edinburgh and Lothians Coarse Angling Club, comfortably beat a field of nine to win the latest weekly match at Magiscroft near Cumbernauld with a bag of 58lb 12oz which consisted mainly of carp.
Scotland have entered two teams in the Sensas Challenge, Britain's premier international team event, on the Gloucester Canal near Quedgley next weekend. The event returns after a two-year break due to COVID-19 and practice is on Thursday and Friday and the match is on Saturday and Sunday. There are 39 teams involved.
Scotland A: Gus Brindle (Dunfermline), James Woodrow (Cumbernauld), David McAuley (Wishaw), James Dornom (Edinburgh), Colin Hart (Coatbridge); Scotland B: Mark Lyons (Clarkston, Glasgow), Scott McGhee (East Kilbride), Derek Brady (Glasgow), Barry Lindsay (Bonnybridge), Barry Young (Torthorwald, Dumfries).
Brindle, the team manager, said: "Sensas Challenge attracts the top teams from across the UK as well as teams from France, Channel Islands, Ireland, Wales and of course Scotland.
"We have always used the event as a development opportunity to allow anglers to step up and represent Scotland in a competition fished to international rules, and to give me the opportunity to see new/emerging talent fishing at this level. This helps to inform selection of squads for Home Internationals, as well as European and World Championship."
Drumtassie open their new coarse ponds on Saturday, March 26, and boss Leeanne Aitchison stressed that it was a day ticket water - adult £10, child £6, extra rod £5 - with species like carp, tench, bream, roach, rudd and ide having been introduced recently. Leeanne said: "The biggest carp going in is 17lb with a mixture of 6lb upwards."
If anglers wish to fish overnight they have to join and the fee is £95. They also have to buy a night ticket for £13 and anglers must be in by 7pm as the gate is locked.
Meanwhile, Drumtassie's popular trout fishery will be closed on Monday, March 21, to pay respects to John Napier whose funeral is on that day in Shotts.
Finally, Far Bank have launched of a series of educational fly fishing videos hosted by the company's education and engagement manager, and well-known fly casting instructor, Simon Gawesworth who said that fly fishers of all experience levels, whether entirely new to fly, novice, improvers, or even advanced fly anglers, will find the videos an online resource. There are episodes on gear, casting fundamentals, fishing techniques, knots, and even what fly fishing is.