United Kingdom Bunkers on the Air (UKBOTA) is an exciting mix of amateur radio and history enabling radio amateurs to ‘activate’ with portable and mobile operations from historic bunker locations and for hunters and chasers to have QSOs with those activating stations (and should they wish to, to ‘collect’ the special ‘bunker reference’ numbers).

ℹ️ UKBOTA is affiliated with the Radio Society of Great Britain (RSGB), as well as being an official affiliated club (AFS) we are also formally recognised as an RSGB Special Interest Group (SIG). You can frequently read about UKBOTA activities in the RSGB’s magazine Radcom and on GB2RS news. UKBOTA is also a club member of the Royal Air Force Amateur Radio Society (RAFARS).

🏆 Free awards for activating and hunting bunkers are available but it’s also okay if you’re not interested in awards and just want to get involved by having a QSO or shortwave listening. Whatever your approach – have fun!

HISTORY

ℹ️ Bunkers on the Air (BOTA) began in 2003 as a unique and innovative way to merge the fascinating world of amateur radio with the rich history of military and civil defence bunkers. It offered radio enthusiasts a chance to not only enjoy their hobby in a new and adventurous way but also to explore and bring attention to often-forgotten historical sites. In the UK, this initiative took on a particular focus on the activation of Royal Observer Corps (ROC) posts—small, often hidden structures that once formed a vital part of Britain’s Cold War defence system. These sites, scattered across the country, have become symbolic of a time when vigilance and communication were at the heart of national security. The original concept of activating bunkers came from Brian G8GMU and his grandson Joshua M3HBM, who, alongside members of the Coventry Amateur Radio Society, began visiting and activating ROC posts in their local area nearly two decades ago. What started as a personal and club-level initiative soon captured the imagination of others in the amateur radio world. By 2010, this grassroots idea had grown in scope and momentum. It was formally brought under the umbrella of the Castles and Stately Homes on the Air (CASHOTA) scheme by Chris Darlington M0DOL, a key figure in developing and structuring portable radio events in the UK. Chris’s work helped standardize the process of “activating” historical locations, encouraging participation, logging, and public engagement. His vision was instrumental in setting the groundwork for what UKBOTA would become. We owe a great deal to the early pioneers of BOTA and related initiatives. Their enthusiasm, dedication, and technical expertise not only preserved important historical heritage but also breathed new life into amateur radio for a new generation. Their contributions laid a solid foundation for the programme’s continued success.

ℹ️ In October 2023, exactly 20 years after the very first UK BOTA activation, the programme saw a powerful and symbolic revival. A special UKBOTA event was held to mark the anniversary, with a particular focus on Royal Observer Corps posts. This event was more than just a celebration—it was a tribute to M0DOL (SK), whose vision and leadership played a critical role in the evolution of BOTA into a recognized and respected part of the amateur radio landscape. It was described by many as “a phoenix rising from the ashes,” as the community came together to breathe new life into the programme.

What followed has been nothing short of extraordinary.

🚀 As UKBOTA continues to evolve, its mission remains clear: to celebrate and preserve our shared history, to promote portable amateur radio operation, and to foster international collaboration. With ongoing support, the programme aims to expand its educational outreach, enhance digital logging tools, and encourage new activators to explore the stories behind the sites they visit.

Whether you’re an experienced operator, a newcomer to radio, or simply someone with an interest in Cold War history, UKBOTA offers a unique way to connect—with the past, with the airwaves, and with each other.

We invite you to join us as we continue to explore the bunkers, shelters, and hidden outposts that shaped our history—and to keep their stories alive, one contact at a time.

Read our free monthly online UKBOTA magazine, packed with news, features and expert advice!

Click here to read the current and previous editions.

New articles always welcome!

There are presently 3759 bunkers on the UKBOTA list. A full searchable list and mapping can be found here.

Where would we be without a few rules!


General Rules

Safety and Permissions

Activators are strongly advised to seek permission from land owners and to conduct a personal safety assessment before conducting an activation.
The listing of of a bunker on our UKBOTA reference list does not in anyway indicate that a bunker, or the vicinity of a bunker, is either safe or legal to enter. Always ask permission.
UKBOTA accepts no responsibility for any issues arising from the activation of a bunker, eg. failing to ensure appropriate access to a site or for matters regarding personal safety.

Terminology

The abbreviation UKBOTA is Copyright and refers to the United Kingdom Bunkers On the Air Award Scheme.

For the purposes of UKBOTA, a bunker is 20th Century fortified or hardened structure for the purposes of positional defence, observation or crisis management. Types of bunkers included in the UKBOTA list include: Royal Observer Corps HQ and Observation Posts, Declassified military and civil defence bunkers, storage and utility bunkers, Airfield Battle HQ, blast shelters, air raid shelters and some pillboxes. Many bunkers are undergound, but by no means all.

A UKBOTA Bunker ‘reference’ is a bunker listed on the UKBOTA Master List, the latest version of the list can be found at www.bunkerbase.org on the Bunker Dashboard.

An activator is a station conducting amateur radio operations from a UKBOTA referenced bunker.

A hunter is a station chasing activator stations, i.e. conducting QSOs with stations located at UKBOTA bunkers as listed in the UKBOTA Master List.

VHF in the context of UKBOTA awards refers to any band above, and inclusive of, 6m (50MHz).

A QSO between two activators at two different bunkers is referred to as a ‘bunker to bunker QSO’ or ‘B2B’ for short.

In some cases it will be possible for an activator to activate more than one bunker at a time. The maximum permitted is 5 at a time. Multi-bunker activation, eg. an activation of 5 bunkers, is often shortened to ‘5fer’ etc.

Valid UKBOTA QSO

A valid UKBOTA QSO must be unassisted. Both stations must be able to copy callsigns, signal reports, and confirmations without the assistance of a third-party station.

Whilst the QSO exchange above describes the minimum requirement for a QSO many activators will chose to give other information. Where possible it is often useful, and of interest to the hunter, to describe a little about the history/geography of the bunker(s) being activated.

The use of WebSDR to receive signal reports under poor band conditions is not permitted.

The use of remote stations by hunter is permitted.

The use of repeaters is not permitted.

Activators and hunters may use any amateur radio band and mode their licence permits.

Operating outside individual licence conditions will render a QSO invalid.

UKBOTA strongly encourages participants to observe the DX Code of Conduct details of which can be found here: https://www.iaru-r1.org/on-the-air/spectrum-abuse/dx-code-of-conduct/

Valid UKBOTA Activation

Generally, an activator requires 25 QSOs on HF or mixed HF/VHF, or 5 on VHF only, to make an activation valid and these activations can be completed over different days. QSO on different bands with the same hunter count as an additional QSO towards the validation requirement. QSO using different modes with the same hunter do not count as an additional QSO towards the validation requirement (unless they occur on a different day). Whilst these general rules cover most awards specific award requirements should also be checked as they may differ.

An activator may not activate from the fixed home station even if it falls within the activation zone, there are two exceptions:

1. An activator may activate from their property if it falls within the activation zone if they are operating away from their main shack and using battery power and not using their main station antennas, eg. ‘garden portable’ or operating from your driveway in your car with mobile radio and antenna.

2. An activator may activate from a bunker activation zone, using mains power and a fixed antenna providing that either a Special Event Callsign or Club Callsign is used.

The use of /P and /M appended to the callsign is no longer required under UK licence conditions and is, therefore, not mandatory for UKBOTA activations.

The use of Regional Secondary callsign prefixes (eg. GM for Scotland) is no longer required following recent changes to UK licence conditions, however, activators are enouraged to use regional prefixes by UKBOTA.

An activator must be ‘activating the bunker’, it is not sufficient to ‘know’ that a station is in an activation zone, if they are not specifically conducting a bunker activation, for it to count as a valid UKBOTA QSO.
The activation zone for a UKBOTA bunker is 1000m, ie. the activator must be within 1000m from the location of the bunker shown on the UKBOTA list. Where possible many activators like to operate from as close to a bunker as possible, noting the importance of safety and site permissions.

A hunter and activator may be within the activation zone of the same bunker for a valid QSO.

Activating more than one bunker at a time

Some bunkers are close together and where there activations zone intersect, ie. within the ‘overlap area’ it is possible to activate both bunkers. In some cases up 5 bunkers (the maximum UKBOTA permit) by all overlap and in the area were they *all* overlap then all 5 may be activated for a 5fer.
Activating other schemes at the same time as UKBOTA

UKBOTA strongly encourages multi-scheme activations, e.g. where the activation location allows, for the activation of a POTA Park, Lighthouse and UKBOTA bunker simultaneously.
Activators are encouraged to check the rules of other schemes for their specific rules and guidelines.
To help keep things clear and focused, we kindly ask that spots are posted on the WWBOTA cluster or bunker-related social media only when the activation includes a bunker. Activations that are parks-only or summits-only should please be spotted via their respective schemes instead.

Getting help

The best and quickest place to ask for help is one of our community forums. We have an active community and in most cases your question will be answered quickly on our Facebook Group or on our our UKBOTA WhatsApp Group. If all else fails, please post a support ticket and one of the admin support team will get back to you as soon as possible.

All radio amateurs in the United Kingdom of United Kingdom of Great Britain and Northern Ireland, plus the Isle of Man and the Channel Islands - including visitors to our shores, our welcome to participate in UKBOTA as actiavtors.

This guide should get you started on your UKBOTA bunker activator journey.

✅ To find suitable bunkers to activate a good start point is the UK Portable Ham Map, see the link on the page and here. Thanks go to Steve Hiscocks, M1SDH for mapping. Steve is also on the UKBOTA Management Team.

✅ Check rules, awards and First Time tip. Note 1000m and typically 25 QSO HF and 5 QSO VHF.

✅ Many bunker activators enjoy to, and are encouraged to, activate bunkers at the same time as references for other schemes, e.g. POTA. The UK Portable Ham Map shows overlays of not only UK bunkers on our ‘Reference list’ but also other popular schemes such as POTA, WWFF and SOTA. A list view of the UKBOTA bunkers, which also includes latitude and longitude, Ordnance Survey Grid Reference, Nearest Postcode and Worked all Britain Square (of the bunker) is here.

✅ Note that each bunker ‘reference’ begins with a ‘B’ and a ‘/’ followed by a country code and then a four digit number. UKBOTA covers bunkers in England (B/G), Scotland (B/GM-), Northern Ireland, Wales, the Isle of Man, Jersey and Guernsey.

✅ Most bunker operations centre on 40m and 20m SSB but other bands are increasingly popular including the higher HF bands, and also VHF and above. CW, FT8 and other modes are also popular – give it a go and call “CQ Bunkers on the Air”. There have been bunker activations in SSB, CW, FT8,FT4, RTTY, PSK and SSTV!

✅ You will find it useful to ‘spot’ yourself (or have someone spot you) when you activate. There are various way to do this either through our internal ‘cluster’, which requires registration to spot but not to view (see the menu above). Many like to use the ‘cluster’ version with the embedded (and quite excellent) fieldspotter.radio map (by Ian Renton, M0TRT) which gives an excellent visualization of WWBOTA spots (as well as POTA and other schemes) and a handy band map for finding other bunkers and having a ‘bunker to bunker’ (B2B) QSO.

✅ Spots made on the WWBOTA ‘cluster’ are automatically forwarded to our bespoke WhatsApp Spots and Alerts Group. The WWBOTA WhatsApp spots and alerts group is here. Please note that group is just for spots and alerts, not general chat.

✅ Self-spots, which are automatically forwarded to our internal ‘cluster’ and the WWBOTA WhatsApp Spots and Alerts Group, may be made using the excellent Ham2K Portable Logger.

✅ If you have any questions about UKBOTA consider joining our social media channels, links are on this homepage.

✅ Finally, watch some of the videos embedded below, they will give you a good idea of what to expect.

⚠️ ⛔ Please Note that UKBOTA takes NO responsibility for safety or right of access issues. If you are unsure then check with the land owner and never activate inside a bunker, or enter private property, or restricted areas, unless you have permission and it is safe to do so.

All radio amateurs and shortwave listeners, worldwide, are very welcome to participate in UKBOTA and of course WWBOTA as hunters (chasers) and to claim free awards.

✅ Find stations calling “CQ Bunkers on the Air” and work them! It’s really that simple!

✅ For UKBOTA Award information see the Awards page linked at the menu at the top of this page

✅ Consider using our internal ‘cluster’ linked above to help you find bunker activations. Note that you do not need to register to view the WWBOTA ‘cluster’ or fieldspotter.radio

✅ Read the Bunker Activator guide, much of that information will also be useful to you.

✅ If you have any questions about UKBOTA consider joining our social media channels, links are on this homepage.

Here at UKBOTA we pride ourselves on provding all particpants with a feature rich and easy to use system. At the heart of the UKBOTA system is a some complex IT system with a powerful database, API and rich user-friendly interface, 95% of users won't be interested in the technology just the we have a really nice interface for you to record,view and manage your UK bunkers related information!

UKBOTA informationis built around 3 types of data:

• *Actiavtor and Activations data
  * Hunter Data
  * Bunker Data
  
  Each of these can be accessed through a dashboard, a dashboard is just a fancy name for a dedicated webpage.

Activator Dashboard 
This is for activators to upload logs (in correctly formatted ADIF files) and to see there UKBOTA Activator 'score'. From the Activator dashboard the activator can find a link to list of all of their activations, awards scores and award claims. A quick link to this dashboard can be found by clicking the purple dashboards button in the right hand corner of the screen. This dashboard can also be found be clicking here.

Hunter Dashboard
This is for hunters to record their QSOs and to see there UKBOTA Hunter 'score'. From the Hunter dashboard the hunters can find a link to a log of all of their UK bunker QSOs, awards scores and award claims. A quick link to this dashboard can be found by clicking the purple dashboards button in the right hand corner of the screen. This dashboard can also be found be clicking here.

Bunker Dashboard
This dashboard is for both activators and hunters to explore our UKBOTA bunkers via either a list or map. Additionally, this dashboard contains a link to the excellent M1SDH Portable Map which provides geographical details for a number of portable schemes including POTA, SOTA and of course UKBOTA. his dashboard can also be found be clicking here.

New to Bunker Spotting? Here’s a Quick Guide!

If you’re just getting started with posting activations, here’s a simple breakdown of how to get your spot out there:

🟢 Option 1: Self-Spot using Ham2K PoLo

This is the easiest and most powerful option. When you self-spot your activation using the Ham2K PoLo portable logger, it’ll automatically send your spot to:

– The Ham2K Spots List
– The WWBOTA Cluster
– Our WWBOTA Spots & Alerts WhatsApp Channel
– www.fieldspotter.radio

🟡 Option 2: Spot Directly on the WWBOTA Website Cluster

Head over to https://wwbota.net/cluster pop your spot onto the cluster (you’ll need to register first, this is not the same as your UKBOTA registration). This will also auto-share your activation to:

– The WhatsApp Spots & Alerts Channel
– www.fieldspotter.org

You can also access our cluster by clicking the purple actions button in the bottom right hand corner of this screen and selecting WWBOTA Cluster

🔴 Option 3: Post Straight into the WhatsApp Spots & Alerts Channel

If your internet isn’t playing ball and you can’t access the cluster, just drop your spot directly into the WhatsApp group. It works — but just a heads-up: this won’t forward your spot anywhere else.

🔥Best bet? Use Option 1 or 2 if you can — they reach the most people automatically.🔥

And of course, you’re always welcome to share your spot manually in other radio chat groups or the main DX Cluster.

🔐 Lost your WWBOTA cluster password? No problem — just ping one of the team and we’ll get it reset for you.

Enjoy the activations & have fun out there!

73, Carl

Introducing the UKBOTA Bunker Atlas. 

One of the things that makes UKBOTA special is the community behind it. Licensed amateur radio operators across the UK activating Cold War bunkers, ROC posts, radar stations and wartime structures — not just logging contacts, but visiting places with real history. For a long time we've wanted a way to capture that knowledge and share it, and today we're doing exactly that.

We're delighted to introduce the UKBOTA Bunker Atlas — a community-built guide to UK bunkers, available now at ukbota.net/atlas.

What is the Atlas?

The Atlas is a living, community-maintained database of bunker cards. Each card brings together everything useful about a specific UKBOTA site — its history, construction, current condition, access notes, activation tips, photos, and a record of how many times it has been activated. Think of it as the field guide we always wished existed when we were planning our own activations.

Cards are linked directly to the WWBOTA database, so coordinates, locator squares and site type are pulled in automatically. When you open a card, you can see the site on an interactive map, browse photos contributed by fellow members, read field reports from activators who have been there, and even get your distance and bearing from your current location.

Built by the community, for the community

The Atlas is only as good as the information members put into it. Any logged-in UKBOTA member can contribute — whether that means writing a description of a site you know well, sharing photos from a recent activation, or submitting a field report about access conditions, parking, antenna options and anything else that might help the next activator.

All contributions are reviewed before they appear publicly, so the information stays accurate and useful. If you've activated a site and learned something others should know, this is the place to share it.

A new way to explore

The Atlas page is designed to be used on any screen — desktop, tablet or mobile. The landing page shows a map of all bunkers that currently have cards, with a live count of how many sites are covered out of the full WWBOTA database. Bunkers updated in the last 24 hours glow on the map so you can see where new information has just been added.

Click any pin and the full card opens alongside the map. You can browse all cards in the sidebar, navigate between them with Prev and Next, and share a direct link to any individual card — useful if you want to point someone to a specific site.

What's there so far

We have made a start, but the Atlas is far from complete — and that's the point. There are over 3,700 bunkers in the UKBOTA database. Each one that gets a card becomes a little more knowable, a little more accessible, and a little more likely to be activated. If you've been to even one of them and have something to add, please do.

How to contribute

Visit ukbota.net/atlas and log in with your UKBOTA account. Search for a bunker reference, open the card, and use the Add Field Report button to share what you know. Photos are very welcome — they really bring a site to life for people who haven't been there yet.

We're looking forward to seeing the Atlas grow. 73 de M0ICR