Stoneflies
Gammarids
- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRHR163
Rules at a glance
- Permit required
- Fly only
Water temperature for Grayling
Warm — slow15°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime.
Where
Faster runs in the middle and lower stretches.
Method
Euro-nymphing through the deeper pockets is the daily default; switch to dries on autumn afternoons when sedges and small olives come off. Long fine tippet for the clear water.
Kit
10 ft #3 nymphing rod for the deep pockets; 9 ft #4 for dries. 4 to 5 lb fluoro tippet, 12 ft leader.
Why this works
Good — water clarity is working for you, but time of day is the limiting factor today.
Likely species
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds as a supporter.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 as a supporter.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
1
2
2
2
2
2
2
1
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
2
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Hook 14–18 · Fly
in season · matches water height
Beats · 1
The Béthune and Eaulne are association water. AAPPMA du Pays de Bray (Pêcheur Brayon) and neighbouring associations hold it, with several fly-only or no-kill stretches. These are day-card waters, not estate beats.
Pêcheur Brayon sectionsDay tickets
The Pays de Bray association manages the first-category sections on both rivers, including fly-only and no-kill parcours.
Visit official site ↗Permits & access
Permit required — see local rules.
- AAPPMA du Pays de Bray and local AAPPMAs share the beats on both rivers
- Fly-only parcours on several stretches
- Check current rules before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Terrain map
Water quality (WFD)
The full read · show the working · for Grayling · confidence 75%
How the 71 is built — score × weight = contribution
Temperature77 × 28%21.6
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time25 × 13%3.3
Pressure80 × 7%5.6
Insect activity68 × 12%8.2
Conditions total= 72
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Arquesproxy
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 2.º Saturday de March → 3.º Sunday de September
- Grayling 3.º Saturday de May → 31 December
France national rule: grayling opens 3rd Saturday of May in all waters. In 2nd category waters, grayling remains open until 31 December. Departmental regulations may impose earlier closing dates. Always check the relevant département's 2026 arrêté préfectoral.
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts
Béthune / Eaulne
Water temperature for Grayling
Warm — slow15°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime.
Where
Faster runs in the middle and lower stretches.
Method
Euro-nymphing through the deeper pockets is the daily default; switch to dries on autumn afternoons when sedges and small olives come off. Long fine tippet for the clear water.
Kit
10 ft #3 nymphing rod for the deep pockets; 9 ft #4 for dries. 4 to 5 lb fluoro tippet, 12 ft leader.
Why this works
Good — water clarity is working for you, but time of day is the limiting factor today.
Likely species
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds as a supporter.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 as a supporter.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
1
2
2
2
2
2
2
1
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
2
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Hook 14–18 · Fly
in season · matches water height
Beats · 1
The Béthune and Eaulne are association water. AAPPMA du Pays de Bray (Pêcheur Brayon) and neighbouring associations hold it, with several fly-only or no-kill stretches. These are day-card waters, not estate beats.
Pêcheur Brayon sectionsDay tickets
The Pays de Bray association manages the first-category sections on both rivers, including fly-only and no-kill parcours.
Visit official site ↗Permits & access
Permit required — see local rules.
- AAPPMA du Pays de Bray and local AAPPMAs share the beats on both rivers
- Fly-only parcours on several stretches
- Check current rules before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Terrain map
Water quality (WFD)
- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRHR163
The full read · show the working · for Grayling · confidence 75%
How the 71 is built — score × weight = contribution
Temperature77 × 28%21.6
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time25 × 13%3.3
Pressure80 × 7%5.6
Insect activity68 × 12%8.2
Conditions total= 72
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Arquesproxy
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 2.º Saturday de March → 3.º Sunday de September
- Grayling 3.º Saturday de May → 31 December
France national rule: grayling opens 3rd Saturday of May in all waters. In 2nd category waters, grayling remains open until 31 December. Departmental regulations may impose earlier closing dates. Always check the relevant département's 2026 arrêté préfectoral.
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts