The 'floating island' lake recorded by Giraldus Cambrensis in 1188 — six hectares above Rhyd Ddu, southwest of Snowdon. SGLL's stocked water, rainbows from one and three-quarter pounds up to five from the Llanrug hatchery, bank and boat fishing, fly only. Historical curiosity meets functional stocked fishery.
A patient day, if you fancy it
Glassy and bright — hard work without a breeze. A flat lough is a quiet lough — wait for the breeze.
Live now
Conditions on the water
Trends shown where the gauge supports them
Some readings unavailable — check directly before fishing.
How to fish · for brown trout
The brief
When · where · method · kit
Today's tactical plan
The plan
Plan A · Plan B · what to watch · bank or boat
With limited drift, anchor or fish static from sheltered positions. Work Dry Fly on the bob and Terrestrial on the point. Drop the droppers and fish a single fly in this wind — tangles cost more time than a second pattern catches.
If the main plan is not working, switch to a smaller, more imitative pattern fished slower and deeper. A change of drift angle can also make a difference.
Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.
Strong wind makes boat fishing difficult — sheltered bank spots near lee shores will fish best.
Hatches & runs
What's on, when
Twelve months at a glance
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Today's fly · curated pack
Top pattern + the box
6 patterns from this venue's curated pack
Evidence
Why today scores what it does
The factors driving today's verdict
- Wind conditions (strong) are not ideal for this water.
- Buzzers are in their seasonal window, boosting the chance of targeted feeding.
Llyn y Dywarchen · profile
Who this water suits
Strengths · watch-outs · best for
Llyn y Dywarchen, on the water
Field guide · contributor-editedLlyn y Dywarchen · about
What this water is
Background · character · contributors
The 'floating island' lake recorded by Giraldus Cambrensis in 1188 — six hectares above Rhyd Ddu, southwest of Snowdon. SGLL's stocked water, rainbows from one and three-quarter pounds up to five from the Llanrug hatchery, bank and boat fishing, fly only. Historical curiosity meets functional stocked fishery.
- Lake
- Ordovician volcanics
Llyn y Dywarchen · directions
How to get to the water
Llyn y Dywarchen

The 'floating island' lake recorded by Giraldus Cambrensis in 1188 — six hectares above Rhyd Ddu, southwest of Snowdon.
A patient day, if you fancy it
Glassy and bright — hard work without a breeze. A flat lough is a quiet lough — wait for the breeze.
Some readings unavailable — check directly before fishing.
Conditions are away from this venue's sweet spot — it usually fishes best in ripple wind with mixed skies.
With limited drift, anchor or fish static from sheltered positions. Work Dry Fly on the bob and Terrestrial on the point. Drop the droppers and fish a single fly in this wind — tangles cost more time than a second pattern catches.
If the main plan is not working, switch to a smaller, more imitative pattern fished slower and deeper. A change of drift angle can also make a difference.
Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.
Strong wind makes boat fishing difficult — sheltered bank spots near lee shores will fish best.
- Wind conditions (strong) are not ideal for this water.
- Buzzers are in their seasonal window, boosting the chance of targeted feeding.
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
The 'floating island' lake recorded by Giraldus Cambrensis in 1188 — six hectares above Rhyd Ddu, southwest of Snowdon. SGLL's stocked water, rainbows from one and three-quarter pounds up to five from the Llanrug hatchery, bank and boat fishing, fly only. Historical curiosity meets functional stocked fishery.
- Lake
- Ordovician volcanics
The 'floating island' lake recorded by Giraldus Cambrensis in 1188 — six hectares above Rhyd Ddu, southwest of Snowdon. SGLL's stocked water, rainbows from one and three-quarter pounds up to five from the Llanrug hatchery, bank and boat fishing, fly only. Historical curiosity meets functional stocked fishery.