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Local Notice to Mariners 25/2026
26/09/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored – Dydd Sul, 27ain o Fedi, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 11:10 o llithrfa Porthaethwy ac yn darfod ar lithfra Y
Felinheli – ETA 13:10.
Bydd nofwyr yn cadw at ochr Ynys Môn ac yn croesi drosodd yn ardal Plas Newydd ETA – 12:40.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Sunday, 27th of September, 2026.
An Open Water Swim Event will commence at 11:10 from Menai Bridge Slipway and finish at Y Felinheli
Slipway – ETA 13:10.
Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd, ETA – 12:40.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 24/2026
26/09/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored – Dydd Sul, 27ain o Fedi, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 10:45 o llithrfa Y Foel (Sir Fon) ac yn darfod ar lithfra Porth yr Aur, Caernarfon – ETA 11:45.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Sunday, 27th of September, 2026.
An Open Water Swim Event will commence at 10:45 from Y Foel Slipway, Anglesey and finish Porth yr Aur Slipway, Caernarfon – ETA 11:45.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 23/2026
25/09/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored – Dydd Sadwrn, 26ain o Fedi, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 10:40 o llithrfa Porth Aethwy ac yn darfod ger Traeth Cerflun Nelson – ETA 12:00. Bydd nofwyr yn cadw at ochr Ynys Môn.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Saturday, 26th of September, 2026.
An Open Water Swim Event will commence at 10:40 from Menai Bridge Slipway and finish at Nelson’s Statue beach – ETA 12:00. Swimmers will be keeping to the Anglesey side.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 22/2026
15/09/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Nid yw cymhorthydd mordwyo Starbord “Traeth Gwyllt” Fl(2)G.10s ar ei safle.
53̊ 09.27 Gog 004̊ 16.09 Gor
Mae’n parhau mewn safle priodol
53̊ 09.36 Gog 004̊ 15.93 Gor
Cynghorir morwyr i fordwyo gyda gofal yn yr ardal hon.
Aid to navigation Starboard “Traeth Gwyllt” Fl(2)G.10s is off station.
53̊ 09.27 N 004̊ 16.09 W
It remains on an appropriate position
53̊ 09.36 N 004̊ 15.93 W
Mariners are advised to navigate with caution in this area.
Local Notice to Mariners 21/2026
30/08/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored – Dydd Llun, 31ain o Awst, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 11:45 o llithrfa Beaumaris ac yn darfod ger Castell Caernarfon – ETA 15:30. Bydd nofwyr yn cadw at ochr Ynys Môn ac yn croesi drosodd yn ardal Plas Newydd.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Monday, 31st August, 2026.
An Open Water Swim Event will commence at 11:45 from Beaumaris Slipway and finish at Caernarfon Castle – ETA 15:30. Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 20/2026
30/08/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored – Dydd Sul, 30ain Awst, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 12:30 o llithrfa Beaumaris ac yn darfod ger Castell Caernarfon – ETA 14:30. Bydd nofwyr yn cadw at ochr Ynys Môn ac yn croesi drosodd yn ardal Plas Newydd.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Sunday, 30th August, 2026.
An Open Water Swim Event will commence at 12:30 from Beaumaris Slipway and finish at Caernarfon Castle – ETA 14:30. Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 19/2026
28/08/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored – Dydd Sadwrn, 29fed o Awst, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 10.45 o llithrfa Beaumaris ac yn darfod ger Castell Caernarfon – ETA 14:30. Bydd nofwyr yn cadw at ochr Ynys Môn ac yn croesi drosodd yn ardal Plas Newydd.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Saturday, 29th August, 2026.
An Open Water Swim Event will commence at 10:45 from Beaumaris Slipway and finish at Caernarfon Castle – ETA 14:30. Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 18/2026
28/08/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored. Dydd Gwener, 28ain o Awst, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 10.15 o llithrfa Beaumaris ac yn darfod ger Castell Caernarfon – ETA 14:00. Bydd nofwyr yn cadw at ochr Ynys Môn ac yn croesi drosodd yn ardal Plas Newydd.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swim Event – Friday, 28th August, 2026.
An Open Water Swim Event will commence at 10:15 from Beaumaris Slipway and finish at Caernarfon Castle – ETA 14:00. Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 17/2026
12/08/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Ar ddydd Sadwrn 15 a dydd Sul 16 o Awst mae Harbwr Caernarfon yn cynnal y OCRDA Rasio Cychod Pŵer blynyddol.
Cynghorir Morwyr y bydd rasio cychod pŵer yn yr ardal tu allan i’r Afon Seiont a Doc Fictoria. Bydd oedi posibl mewn gall llywio i mewn ac allan o’r Afon Seiont a Doc Fictoria. Byddwch yn amyneddgar a dilynwch geisiadau’r swyddogion os gwellwch yn dda.
Mae mordwyo y tu mewn i’r ardal GLAS yn gwahardd yn llym yn ystod yr amseroedd rasio.
Cysylltwch â Meistr Doc am ragor o wybodaeth ar y diwrnodau rasio. VHF ch 80
Gall amseroedd newid ar fyr rybudd
On Saturday the 15th and Sunday the 16th of August Caernarfon Harbour is hosting the annual OCRDA Powerboat racing.
Mariners are advised that there will be Powerboat and Jest ski racing in the area outside the River Seiont and Victoria Dock. There will be potential delays in being able to navigate inbound and outbound of both the River Seiont and the Victoria Dock. Please be patient and follow the official’s requests.
Navigation inside the BLUE area is strictly prohibited during the racing times.
Please contact the Dock Master on VHF ch80 for further info on the race days.
Timings are subject to change at short notice
Local Notice to Mariners 16/2026
03/08/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae yr cymhorthydd mordwyo Aber Menai Point ar ei safle priodol ac yn nawr yn dangos goleuadau priodol.
53̊ 07.62 Gog 004̊ 19.72 Gor
Cynghorir morwyr bod yr hysbysiad hwn yn dileu Hysbysiad 15/26.
Aid to Navigation Aber Menai Point is on station and is now demonstrating its appropriate light characteristic.
53̊ 07.62 N 004̊ 19.72 W
Mariners are advised that this notice herby cancels Notice 15/26.
Local Notice to Mariners 15/2026
29/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae yr cymhorthydd mordwyo Aber Menai Point ar ei safle priodol ac yn nawr yn dangos goleuadau priodol.
53̊ 07.31 Gog 004̊ 23.89 Gor
Cynghorir morwyr bod yr hysbysiad hwn yn dileu Hysbysiad 14/26.
Aid to Navigation Aber Menai Point is on station and is now demonstrating it’s appropriate light characteristic.
53̊ 07.31 N 004̊ 23.89 W
Mariners are advised that this notice herby cancels Notice 14/26.
Local Notice to Mariners 14/2026
28/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae yr cymhorthydd mordwyo Aber Menai Point ar ei safle priodol ond nid yw yn dangos goleuadau priodol.
53̊ 07.62 Gog 004̊ 19.72 Gor
Cynghorir morwyr i fordwyo gyda gofal yn yr ardal hon.
Aid to Navigation Aber Menai Point is on station but not showing it’s appropriate lights.
53̊ 07.62 N 004̊ 19.72 W
Mariners are advised to navigate with caution in this area.
Local Notice to Mariners 13(2)/2026
23/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae cymhorthydd mordwyo Starboard Rhif C3 QG ar ei safle priodol..
53̊ 07.31 Gog 004̊ 23.89 Gor
Aid to navigation Starboard No C3 QG is on its appropriate station.
53̊ 07.31 N 004̊ 23.89 W
Local Notice to Mariners 13/2026
12/06/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Digwyddiad Nofio Dŵr Agored. Dydd Sadwrn, 18fed Gorffennaf, 2026.
Bydd Digwyddiad Nofio Dŵr Agored yn cychwyn am 13:50 o llithrfa Porthaethwy ac yn darfod yn Y Felinheli – ETA 15:50. Bydd nofwyr yn cadw at ochr Ynys Môn ac yn croesi drosodd yn ardal Plas Newydd – ETA 15:20.
Bydd caiacwyr diogelwch a chychod modur yn eu hebrwng.
Byddwch yn ofalus wrth lywio yng nghyffiniau’r digwyddiad.
Open Water Swimming Event. Saturday, 18th July, 2026.
An Open Water Swimming Event will commence at 13:50 from Menai Slipway and finish at Y Felinheli – ETA 15:50. Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd – ETA 15:20.
They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Local Notice to Mariners 12/2026
16/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Afon Menai – Menai Strait
Mae cymhorthydd mordwyo Starbord “Traeth Gwyllt” Fl(2)G.10s ar ei safle newydd.
53̊ 09.24 Gog 004̊ 16.06 Gor
Aid to navigation Starboard “Traeth Gwyllt” Fl(2)G.10s is on its new station.
53̊ 09.24 N 004̊ 16.06 W
Local Notice to Mariners 11/2026
09/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae cymhorthydd mordwyo Starboard Rhif C3 QG ar ei safle priodol ac nawr wedi heb oleuni.
53̊ 07.23 Gog 004̊ 23.88 Gor
Cynghorir morwyr bod yr hysbysiad hwn yn dileu Hysbysiad 09/26.
Aid to navigation Starboard No C3 QG is on its appropriate station and is now lit.
53̊ 07.23 N 004̊ 23.88 W
Mariners are advised that this notice herby cancels Notice 09/26.
Local Notice to Mariners 10/2026
09/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae cymhorthydd mordwyo Port Rhif C2 Fl.R 10s ar ei safle priodol ac nawr wedi oleuni.
53̊ 07.17 Gog 004̊ 24.32 Gor
Cynghorir morwyr bod yr hysbysiad hwn yn dileu Hysbysiad 07/26.
Aid to navigation Port No C2 Fl.R 10s is on its appropriate station and now lit.
53̊ 07.17 N 004̊ 24.32 W
Mariners are advised that this notice herby cancels Notice 07/26.
Local Notice to Mariners 09/2026
07/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae cymhorthydd mordwyo Starboard Rhif C3 QG ar ei safle priodol ac ar hyn o bryd heb oleuni.
53̊ 07.23 Gog 004̊ 23.88 Gor
Cynghorir morwyr i fod yn ofalus yn y ardal hwn.
Cynghorir morwyr bod yr hysbysiad hwn yn dileu Hysbysiad 08/26.
Aid to navigation Starboard No C3 QG is on its appropriate station and currently unlit.
53̊ 07.23 N 004̊ 23.88 W
Mariners are advised to exercise caution in this area.
Mariners are advised that this notice herby cancels Notice 08/26.
Local Notice to Mariners 08/2026
06/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae cymhorthydd mordwyo Port Rhif C3 QG ar ei safle priodol ac ar hyn o bryd heb oleuni.
53̊ 07.23 Gog 004̊ 23.88 Gor
Cynghorir morwyr i fod yn ofalus yn y ardal hwn.
Aid to navigation Port No C3 QG is on its appropriate station and currently unlit.
53̊ 07.23 N 004̊ 23.88 W
Mariners are advised to exercise caution in this area.
Local Notice to Mariners 07/2026
06/07/2026 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Mae cymhorthydd mordwyo Port Rhif C2 Fl.R 10s ar ei safle priodol ac ar hyn o bryd heb oleuni.
53̊ 07.17 Gog 004̊ 24.32 Gor
Cynghorir morwyr i fod yn ofalus yn y ardal hwn.
Aid to navigation Port No C2 Fl.R 10s is on its appropriate station and currently unlit.
53̊ 07.17 N 004̊ 24.32 W
Mariners are advised to exercise caution in this area.
Longterm Notices to Mariners
Local Notice to Mariners 11/2025
01/04/2025 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
Longddrylliad “Grampian Castle” Wreck
Mae Cardinal De sefydlog newydd VQ(6) + LFl 10s (Castell Grampian) wedi osod ar longddrylliad “Grampian Castle”.
53ᵒ07.30′ Gog 004ᵒ22.99′ Gor
A new Fixed South Cardinal VQ(6) + LFl 10s (Grampian Castle) has been affixed to the wreck of the “Grampian Castle”.
53ᵒ07.30′ N 004ᵒ22.99′ W
Local Notice to Mariners 24/2024
30/08/2024 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Bar Caernarfon Bar
“BANC CREGYN GLEISION”
Mae nawr Cymorth Mordwyo Port newydd ar Mussel Bank, ac mae bellach yn dangos siâp dydd priodol a golau Fl R(2)5s yn y sefyllfa ganlynol.
53ᵒ07.320′ Gog 004ᵒ20.926′ Gor
“MUSSEL BANK”
A new fixed Port Aid to Navigation on Mussel Bank, has been completed and is now demonstrating an appropriate day shape and light Fl R(2)5s is the following position.
53ᵒ07.320′ N 004ᵒ20.926′ W
Local Notice to Mariners 19/2021
02/07/2021 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Cynghorir morwyr bod yr ardal a amlygir isod ar y siart, yn benodol o amgylch C7 ac C12 wedi datblygu banc tywod sydd rhyw 1 metr yn uwch na Chart Datwm.
Cynghorir morwyr i gymryd rhybudd a rhoi sylw dyledus i’r dyfnder dŵr sydd ar gael wrth fordwyo yn yr ardal hon.
Mariners are advised that the area highlighted below on the chart, specifically around C7 and C12 has developed a sand bank that is approximately 1 meters above Chart Datum.
Mariners are advised to take caution and have due regard for the available depth of water when navigating in this area.
Local Notice to Mariners 12/2021
01/04/2021 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Harbour Master’s General Direction
5 Knot Speed Limit
By virtue of the provisions of Sec. 52 Harbour, Docks and Piers Clauses Act 1847, Port and harbour of Caernarfon Harbour Master has made the following General Direction:
1. This Direction is given to Masters (see note a) and persons having command or charge of any vessel (see note b) other than those vessels listed in paragraph 4(i) to 4(v).
2. This Direction applies at all times and in the area north of the existing and active speed limit at Y Felinheli. (Now known as the “Y Felinheli to Garreg Ginnog” Area of General Direction). The “Y Felinheli to Garreg Ginnog” means the area below the level of mean high water spring tides bounded by a line drawn along the northern extent of the existing charted speed limit at Y Felinheli and through to a new line drawn from a point 53ᵒ12.30’N 004ᵒ12.44’W to a point 53ᵒ12.40’ N 044ᵒ12.82’W. (Illustrative chart extract at end of NtoM).
3. At the Northern and Southern extent of the entire speed limit. Special Marks will be positioned to demark the area.
4. This Direction is not given to Masters and persons having command or charge of vessels:
(i) used by search and rescue organisations
(ii) of the Caernarfon Harbour Authority
(iii) of HM Customs and Excise
(iv) vessels under sail.
(v) used as safety boats by Yacht and Sailing Clubs and other such organisations when engaged in operations where complying with this Direction would inhibit their ability to fulfil their function as a safety boat
5. No vessel, except those listed in paragraphs 4(i) to 4(v), shall proceed at a speed of greater than 5 knots.
6. This Direction is given notwithstanding the requirements of the International Regulations for Preventing Collisions at Sea (see note c) and The Port and Harbour of Caernarfon Bylaws 1991 (see note d).
7. Not to comply with this Direction is a criminal offence for which the person having command or charge of the vessel may be prosecuted (see note e).
8. The Harbour Master or his deputies will be actively monitoring the compliance with this General Direction.
David John O’Neill
Caernarfon Harbour Master
Notes
a Sec.3 Harbour, Docks and Pier Clauses Act 1847
b As defined in the Port and Harbour of Caernarfon Bylaws 1991.
c Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations 1996 [SI 75/1996]
d Port and Harbour of Caernarfon Bylaws 1991.
e Sec.3 and Sec.53 Harbour, Docks and Piers Clauses Act 1847
Owners, Agents Charterers, Marinas, Yacht Clubs and Recreational Sailing Organisations should ensure that the contents of this Notice are made known to the master or persons in charge of their vessel or craft.
Blue area denotes existing speed limit. Yellow area denotes new area of General Direction.
Local Notice to Mariners 14/2019
16/05/2019 – Y Fenai – Siart 1464 – Menai Strait – Chart 1464
Menai Strait
Cynghorir morwyr bod yr ardal a amlygir isod ar y siart, yn benodol o C11 er i C9 wedi datblygu banc tywod sydd rhyw 0.5 metr o ddŵr yn is na Chart Datwm.
Cynghorir morwyr i gymryd rhybudd a rhoi sylw dyledus i’r dyfnder dŵr sydd ar gael wrth fordwyo yn yr ardal hon.
Mariners are advised that the area highlighted below on the chart, specifically from C11 though to C9 has developed a sand bank that has approximately 0.5 meters of water below Chart Datum.
Mariners are advised to take caution and have due regard for the available depth of water when navigating in this area.
