The National Diving & Activity Centre

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Notice of NDAC Chepstow site closure

The National Diving & Activity Centre (NDAC) Chepstow site is permanently closed.

We’d like to thank all our customers for their support over the years.

Notice of site closure

The National Diving & Activity Centre is permanently closed. We are not taking bookings for leisure activities or public diving.

We’d like to thank all our customers for their support over the years.

Activities & Events

Site Facilities

Diving Information

Centre Information

National Diving & Activity Centre
NP16 7LQ

NDAC Emergency Procedure Information

Contact Details

The National Diving & Activity Centre
Tidenham Quarry
NP16 7LQ
Email NDAC Contact Form

Nearest Telephone and Communications Locations at site

National Diving & Activity Centre Main Facilities Building:

The View Café Bar:

NDAC Panic Alarm SystemThe water & floating pontoon areas are covered by all UK mobile phone networks. However, like most rural locations, reception may vary in specific areas. It is advised you check your mobile network if using this as a line of communication for your dive project/plan.

The site is a rural location and the water area is 34m below the car park. The lake is surrounded by limestone walls over 200ft in height.

NDAC staff carry hand-held radios and link to the main building and main line phone at all times.

The Emergency Panic push button alarm system on the floating pontoons is linked into the main site's intruder alarm system if activated.

To activate the alarm push the button with your hand. A radio link will activate the alarm at the centre so centre staff know there is an incident. There is also a hand held radio in the blue shed if required to speak to NDAC staff.

CCTV is in operation throughout the site 24 hours a day and monitored for the purposes of crime prevention and public safety. This scheme is controlled by the National Diving & Activity Centre. For further information please contact us.

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Emergency Services 

Dial 999 or 911

HM Coastguard Channel 16 or 999

Maritime Coastguard Agency (Beachley) 01291 626 814

If the incident is diving related, the emergency services will respond and NDAC will advise DDRC who in turn will give clear direction on medical advice in cooperation with first aid staff and attending emergency services.

Any blue light/emergency service asset dispatched to the NDAC will be coordinated by NDAC staff during public opening by day and by night.

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NDAC Site Description

Dayhouse Quarry NDAC OS Map2 Miles East of Chepstow on the A48. NDAC Location Map and Directions>

Map Reference Sheet 162 Grid 552955. NDAC OS Map>

GPS 55238 / 95854

Quarry runs North – South / East – West

Car Park at southern end of site

Hazards Telegraph pole 30 meters south of landing zone

NDAC Site Plans and underwater maps>

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Nearest Recompression Chambers

The nearest Chambers to the National Diving & Activity Centre are as follows:

Plymouth (DDRC): The Hyperbaric Medical Centre
Tamar Science Park
Research Way, Derriford
Plymouth, Devon

Principal Medical Director: Dr. Phil Bryson
Daytime Telephone No: 01752 209 999
Emergency Telephone No: 08702 385 001
24 Hour Cover: Yes
Chamber Proximity to Supporting Hospital: Adjacent to Derriford Hospital
Name and Address of Supporting Hospital:

Derriford Hospital
Derriford Road
08451 558 155

Chamber Proximity to Helicopter Winch Point: On Site
Time to Mobilise Chamber: 40 Minutes
Category of Chamber: Category 1 and 4
Responsible Health Authority or Trust: Plymouth NHS Trust 

Wirral: North West Emergency Recompression Unit
Murrayfield Hospital, Holmwood Drive
Thingwall, Wirral
CH61 1AU
Principal Medical Director: Dr. John Harrison
Daytime Telephone No: 0151 648 8000
Emergency Telephone No: 0151 648 8000
Chamber Proximity to Supporting Hospital: On Site (not a BUPA chamber)
Name and Address of Supporting Hospital:

Murrayfield Hospital
Holmwood Drive
CH61 1AU
0151 648 7000

Chamber Proximity to Helicopter Winch Point: On Site
Time to Mobilise Chamber: Less than 30 mins
Category of Chamber: Category 1
Responsible Health Authority or Trust: Not Applicable

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Specialist Hyperbaric Advice

DDRC, Plymouth

Tel 01752 209 999

The Diving Diseases Research Centre (DDRC), is a charity which aims to promote and take part in the medical treatment, training and research associated with the use of hyperbaric oxygen in the treatment of diving diseases and other medical problems.


Capital Hyperbarics, London

Tel 07623 937 666


The Diver Clinic

Tel 07770 423 637

Hyperbaric Chamber and Recompression Services in Poole and Reading. The Diver Clinic provide a recompression service for divers with decompression illness (the bends). If you wish to contact us concerning symptoms, our hyperbaric chamber or the medical treatment of diving injuries, please call our emergency number shown above.

London Diving Chamber, London

Tel 07940 353 816

The London Diving Chamber, a Hyperbaric decompression chamber offering NHS funded recompression to divers with Decompression Sickness (DCS) together with other Hyperbaric Oxygen Therapy (HBOT) treatments.

London Diving Chamber specialises in Diving Medicine and provides a 24 hour clinic with everything a diver could need from a medical facility.

British Hyperbaric Association

The aims and objectives of the BHA are as follows:
To promote the understanding and safe practice of hyperbaric medicine
To provide a forum for discussion of hyperbaric therapy in the British Isles, with particular consideration of:

  • Clinical indications
  • Therapeutic standards
  • Audit and research
  • Funding
  • Management

To self regulate member chambers, so that hyperbaric oxygen therapy is delivered in an appropriate and safe manner to patients, and that member chambers work within accepted clinical and technical standards and legislation.

To encourage the exchange of information on treatment problems, a common database, the best use of resources available, and methods of closer unification.

To encourage a method by which peer group review is acceptable and current medical advances are disseminated.

To discuss methods of achieving long term financial support.


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DAN: Divers Alert Network

DAN helps divers in need, 24/7, anywhere in the world, with medical emergency assistance, and promotes diving safety through Research, Education, Products and Services.

Emergency 0870 871 9999
Support 0870 872 8888

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Nearest Accident and Emergency (A&E) Hospitals

The National Diving & Activity Centre (NDAC Ltd) is situated in Tidenham, on the edge of Gloucestershire and is only 1.5 miles from the border of Chepstow, Wales.

We sit between 2 major hospitals within a 20-mile radius of the site: Royal Gwent (19.4 Miles) & Southmead (16.7 miles). There is also a local A&E at Lydney Hospital within 8 mile of the site.

The choice of hospital and the route taken by blue light services could be affected by a number of variables:

• Volume of traffic in city areas, local road networks and M4/M48/M5 motorways.
• Time of day
• Major events in the area
• Bridge closures

The emergency department selected may not always be the one closest to the NDAC. However, blue light services will liaise with the NDAC and advise where any casualty will be taken.


Lydney & District Hospital (Minor Injuries)

Lydney & District Hospital is situated on the northern edge of Lydney town center on the A48 road from NDAC Ltd

7.6 miles by road with a travel time of 13 minutes by road

The hospital is open for Minor Injuries only from 0800 - 1800hrs

Lydney & District Hospital
22 Grove Road
GL15 5JF

01594 598 244


Royal Gwent Hospital (Major / Minor Injuries)

Royal Gwent District Hospital is situated on the western edge of Newport town centre on the A48 main road to Cardiff.

19.4 miles by road with a travel time of 27 minutes by road

Open 24 hours (Major/Minor Injuries)

Cardiff Road, Town Centre
Newport, Gwent
NP20 2UB
01633 234 234


Southmead Hospital (Emergency Department (ED) & Minor Injuries Unit (MIU))

Southmead Hospital Bristol is situated in the northern suburbs of Bristol and has an Emergency Department (ED) and Minor Injuries Unit (MIU)

16.2 miles by road with a travel time of 26 minute by road via M48 Severn bridge.

Open 24hours (Major / Minor Injuries)

Southmead Road,
Bristol, Avon.
BS10 5NB
01173 408 400

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Oxygen Therapy Units

You are to ensure you provide your own Oxygen Therapy Units for any diving related works / training you undertake at NDAC.

NDAC hold such units for emergency use only in the following areas:

• Inside main building at NDAC x 2
• Inside the Floating Pontoon Blue Shed (Waterside) x 2 (when open to the public)

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First Aid /Kits

First Aid Kits can be found:

• Inside the NDAC (main building)

• Inside the Floating Pontoon Shed (Waterside)

• Inside all vehicles

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We have up to 3 defibrillators on site:

1. A community defibrillator is located by NDAC main gate. Access to this is via 999.
2. A secondary defibrillator is kept inside the Floating Pontoon Blue Shed (waterside), when open to the public.
3. A third defibrillator isavailable in the Aqua park shed, when open to the public.

Emergency rescue & first aid equipment such as rescue sledges, spine boards, stretcher and blankets are available in the Floating Pontoon Blue Shed.

We also have a Safety Support Boat (waterside)

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NDAC Environmental Impact Features

Water Type
Fresh water, non-tidal, spring fed

Minimum TBC
Maximum TBC
Average TBC

Minimum < 1m
Maximum > 22m+

Visibility Effectors
Time of Year
Kicking up Silt
Heavy Rainfall

Depth Range
Minimum 1m
Maximum 82m
Average 10m - 30m
Dependant on the time of year, depth can vary by around 1.0- 1.5 metres

Bottom Composition
Large Limestone Rocks (please refer to shop map of quarry before it flooded)

Underwater Obstructions
Swim through (Plastic tube tunnels)
Aircraft wreckage (various)
Vehicle wreckage (various)
Steel Training platforms (various)
Diving bell
Large drop off from 30 shelf to 50m
Large drop off from 50 shelf to 80m

Entry & Exit Points
Various - most giant stride with a number of spine ladder exits (please refer to site map for locations)
A concrete slipway is under construction

Environmental Impact Study           
A detailed Environmental Impact Study has been completed   



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Useful Site Numbers

Site Office
Tel: 01291 630 046

Mr D Bryce MBE


Version 2c
Updated 01 April 2019




National Diving & Activity Centre, Tidenham, Chepstow, Gloucestershire, NP16 7LQ. Tel:    Email | Website & Design by Studio JERO