An Open Water Swimming Event will commence at 10:40am from Menai Slipway and end at Y Felinheli – ETA 12:40pm . Swimmers will be keeping to the Anglesey side and will cross over at Plas Newydd – ETA 12:10pm . They will be accompanied by safety kayakers and powerboats.
Please exercise caution when navigating in the vicinity of the event.
Jennifer Jones Harbwr Feistr Cynorthwyol Caernarfon Assistant Harbour Master Ymddiriedolaeth Harbwr Caernarfon Harbour Trust
The Environment Agency/Briggs Marine are scheduled to undertake a small scale scientific survey (sediment grab sampling) from the vessel Severn Guardian.
Survey Details
Survey Period: 20/05/2026 – 31/06/2026 Survey duration: 1 day Time on station: 15-60 mins Survey Vessel: Severn Guardian Skipper: Mark Williams Survey Officer: Richard Pritchard [email protected]
Station
OSGB36 Easting
OSGB36 Northing
OSGB36 OS Reference
WGS84 Lat DD.DDDDDD
WGS84 Long DD.DDDDD
WGS84 Lat DD°MM.MMM’M
WGS84 Long DD°MM.MMMM’
Cefni_01
237443.7
364727.3
SH 37444 64727
53.1547851
-4.4325676
53°09.2871’N
4°25.9541’W
Cefni_02
238436
363340.4
SH 38436 63340
53.1426315
-4.4170494
53°08.5579’N
4°25.0230’W
Cefni_03
238018.1
364197
SH 38018 64197
53.1502037
-4.423717
53°09.0122’N
4°25.4230’W
Cefni_04
237972.5
363473.7
SH 37972 63474
53.1436920
-4.4240408
53°08.6215’N
4°25.4424’W
Cefni_05
237378.2
364262.1
SH 37378 64262
53.1505889
-4.4333124
53°09.0353’N
4°25.9987’W
David John O’Neill Harbwr Feistr Caernarfon Harbour Master Ymddiriedolaeth Harbwr Caernarfon Harbour Trust
All mariners are advised that The Environment Agency/Briggs Marine are scheduled to undertake a small scale scientific survey (sediment grab sampling) between 1st June – 31st June 2026 in Conwy Bay and Red Wharf Bay from the vessel Severn Guardian.
Date: 1st June – 31st June 2026. The surveys are likely to be done between 12th June to 15th June.
Duration : 1 Day
Activity: Day grabs at 2 locations in Conwy Bay/Estuary and 2 locations in Red Wharf Bay.
Notice of Exempted Activities for scientific instruments Connecting Conwy research project – Scientific monitoring
An underwater video survey will take place on 01 April 2026 (weather dependent) within the licensed area of licence Ref: DEML2284. A copy of the location and coordinates are below. The equipment will be deployed from Bangor University vessel, Macoma, over slack high water and recovered after 2 hours. The vessel will remain in the area throughout to monitor the equipment. The equipment will be marked with surface buoys. It should be noted that these are not for any navigational warning purposes.
The Environment Agency/Briggs Marine are scheduled to undertake a small scale scientific survey (sediment grab sampling) from the vessel Severn Guardian.
Survey Details
Survey Period: 07/04/2026 – 23/04/2026 Survey duration: 1 day Time on station: 15-60 mins Survey Vessel: Severn Guardian Skipper: Mark Williams Survey Officer: Tom Lord [email protected]
The Environment Agency/Briggs Marine are scheduled to undertake a small scale scientific survey (sediment grab sampling) in the Caernarfon Bay area from the vessel Severn Guardian.
Survey Details
Survey Period: 07/04/2026 – 23/04/2026 Survey duration: 2 days Time on station: 15-60 mins Survey Vessel: Severn Guardian Skipper: Mark Williams Survey Officer: Tom Lord [email protected]
Mariners are advised that between 8 March 2026 and 14 March 2026 there will be heightened commercial vessel traffic operating in the area identified on the above chart, particularly during periods around low water slack.
This traffic will include barges and seagoing tugs which may need to hold sta on for extended periods. All vessels and barges will be displaying the appropriate day shapes or lights.
Mariners should navigate with caution and maintain a safe distance from the vessels. If in any doubt, mariners should make contact with the standby vessel Delta2 on VHF Channel 16.
Overnight, large vessels will be anchored in the vicinity of the marked ‘X’, displaying the required anchor lights.
For press enquiries: Press Office – UK Highways: Call 0844 693 1448 – this is a 24/7 number. Journalists are requested not to contact individual departments. The Press Office will assist and arrange an appropriate spokesperson if required and may be contacted on 01248 752130 or 01248 752128.
This notices self-cancels at 11:59pm on 14 March 2026.
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.
