Stage 1: Richard starts by tying in some 8/0 red uni thread, starting at the head. He then ties in a small butt using Glo-floss. This is luminescent and can be charged up with a torch or UV light as required. The Cosseboom is originally a salmon fly. It was created in 1923 by American angler John C. Cosseboom. He lived in Woonsocket, Rhode Island but he used the fly fishing for salmon in the rivers of Nova Scotia. It remains a very popular and effective Atlantic Salmon fly and is used worldwide.

Stage 2: Richard now uses holographic silver for the body of the fly, starting at the head and then tying in at the butt end. It is then wound around the body and secured at the head.

Stage 3: Next is the hackle, and yellow cock feathers seem to work well in this variant. Richard adds a dab of superglue – this helps make the fly more resilient to repeated maulings by sea trout.

Stage 4: The wing is grey squirrel, tied in behind the head. Richard gently persuades it into position before adding another dab of glue to the thread.

Stage 5: 3 strands of Crystal Flash are added over the wing. These help to give the fly more movement and attraction. It's starting to look like a fly that might catch a fish!

Stage 6: Next, Richard ties in jungle cock eyes. This is optional but it certainly makes the finished fly look more attractive – hopefully to the fish but definitely to the angler! Finally, a whip finish to create a neat head and then finished with clear varnish. And there it is, the Cosseboom Variant as tied and used by Richard Roberts of Rhyl and St Asaph Angling Association.

This sillhouette view perhaps shows how a sea trout might see the fly at dusk on the river Clwyd – never the clearest of rivers. You can see how effective the glo-floss butt is, and this could make all the difference between attracting a take and not. This fly can be used on the dropper or the tail.

Here are some that Richard has tied in sizes 12 to 6......

.....on single and double hooks, and aluminium tubes.

Richard stumbled across this variant pattern about four seasons ago. It's been quite successful for him in the early part of the Clwyd sea trout season, towards the end of June when the main runs are starting. In fact Richard said it's his go-to fly for the first few weeks of the sea trout season. Finally, a big thank you to Richard for sharing this great fly with us. Materials needed to to this fly: 8/0 red uni thread Glo-Floss Holographic silver Yellow dyed cock feathers Grey squirrel hair Crystal Flash Jungle cock eye Superglue Clear varnish Hook Sizes: 12 to 6 Aluminium Tubes: 1" - 1.5" See you next time!