Submarine Command and Control

Imagine sitting on a battlefield blindfolded and trying to figure out what is happening with only your ears to guide you; your guidance is based on orders written weeks or months ago, and the last time you got an update of where your own forces where was a day old (at best). That, in essence, is submarine warfare. There is no constant information flow for situational awareness and communication (of any kind) endangers your existence; so submarine commanders are required to make decisions based on a series of assumptions about a myriad of variables and use their experience, judgement, advice from their team, and a deep understanding of their adversary.

In an era of militaries imagining a one-size-fits-all approach to command and control, there remain many areas of military operations that cannot operate in such a fashion. Submarine operations is one of those areas: The battlespace they operate in, their way of operating, and the behaviours of the electro-magnetic spectrum in the underwater domain dictate some bespoke arrangements.

Fighting in the underwater domain is both discombobulating and disturbing. Not only do submarines usually operate alone (their most lethal asset – besides the people that operate them – is their ability to remain undetected and pose an unseen threat to adversaries), but they also do so at huge geographic distances from their operating bases and their higher headquarters. There is an inherent isolation from both higher command or other units: that inability to communicate is not simply the idea of real time (or even near real time) data and communications exchange, but usually involves delays of at least 24 hours (for urgent contact), or much longer during covert missions.

The lack of communications is only in part a choice: being immersed in saline of varying temperatures means that the whole electro-magnetic spectrum behaves differently. And it is a very noisy place. EM waves do indeed exist below the surface but only at much lower frequencies, and they behave in different ways too. To communicate, data must be sent at very low frequencies in order to penetrate and endure passage through salt water, which means an inordinately slow speed of passing information (through water laser communications go no further than hundreds of yards). But it is more complex than that: the characteristics of water columns differ in different geographic locations, and it is dynamic too, constantly changing. Sometimes these changes are gradual and barely noticeable, in other parts of the ocean they can alter very suddenly, appearing almost like unseen walls in the water, changing with the character (salinity and temperature) of the surrounding sea. On occasions the differences between two water columns can be so great that the pressure change can cause a 10,000 ton submarine to drop hundreds of feet in depth as it passes through them. It is rather more disturbing than turbulence experienced in flight. Aside from the danger inherent in that, it also means that comms pathways are not linear and can behave in unexpected ways.

This is ‘normal’ for submariners but it has implications for command and control. Communications underwater take time and risk detection – a submariners greatest fear.

The implications of long-haul and extraordinarily slow communications are notable. The lack of up-to-date situational awareness incurs penalties in receiving and updating orders from higher headquarters, and of providing feedback. Of course, there are alternatives to very slow, long-haul underwater communications at low frequency, very low frequency, and extremely low frequencies. Satellite communications can be used when the submarine is near the surface but these appear – to everyone monitoring – as unique identifiers in a literal ocean of electro-magnetic silence: these mediums of communications will be avoided unless absolutely necessary. Modern SLOT buoys can provide time-delayed satellite updates to commanders, allowing a submarine to clear the datum of transmission, but the submarine can still be geographically localised because of them: avoidance of any communications is the preferred modus operandi for submarines.

As a result, submariners are often referred to as the silent service. This is not only a reference to the way they hope their boats behave – acoustically and electromagnetically silent from enemies – but also how they as individuals can often come across to the public. Even within gatherings of wider service personnel, submariners tend to be found as a separate group; one not defined by rank, peers, engineering specialisation, or as campaign veterans, but with other submariners.

They are, without doubt, the most professional bunch of people you will meet – inside the military or outside it: focused, driven, cerebral, quick witted, often amusing, but usually deadly serious. Their stock and trade is to operate alone and unafraid in the most treacherous of places. Even a military exercise is hazardous to a submariner in a way that it just isn’t for any other sailor, soldier or aviator.

To exist in a metal tube for weeks and months non-stop, with few ports to stop in, puts all submariners under pressure. But there is something else too: to be under constant awareness that the wrong decision could mean death for the entire crew with no escape is something else; your reliance and dependence on the ability of your shipmates to respond to any emergency – no matter their specialisation, is total. These tensions mean that submariners are required to have an understanding of every part of their boat – even those outside their specialist trades – that simply cannot be replicated for those in any other service, or in other parts of a naval force.

The nature of the underwater battlespace means that traditional command and control means don’t work. Not even the most novel, disruptive or ‘transformative’ technologies can overcome the barriers of water, salinity, temperature gradients, and depth. It is a world where any communication is an aberration rather than the norm; where the idea of shared situational awareness is an anathema.

The first part of understanding how submarine C2 is different starts with the different types of submarine and their specific mission. For nuclear ballistic missile firing submarines, command and control forms a core part of strategic deterrence theory, underpinning the credibility of national deterrence strategies. Independent operations, secrecy, secure communications, and non-detection form vital elements of their mission. During a patrol, communications are normally one way (from a national headquarters to the submarine).

Hunter-killer submarines (nuclear powered, non-ballistic missile firing SSNs), can be used in direct support to major naval task groups – either carrier strike groups or amphibious forces. In such cases, SSNs operations need to be deconflicted through the embedded Submarine Element Co-ordinator and Submarine Advisory Team: the tasking authority for submarines in Direct Support to a naval task group will depend on who has been delegated specific C2 duties. When in Direct Support, SSNs may use higher frequencies (HF, UHF, VHF) for updates and deconfliction. Yet the most effective use of SSNs is employment on independent operations: freed from the shackles of geographic limitations imposed by task groups this is when SSNs are at their most effective, released to hunt and kill adversaries.

Under such circumstances, communications revert to a one-way broadcast at LF/VLF and ELF frequencies. The data rate is very slow, often ponderous. The time between communication with a deployed vessels can be a day – or much, much longer. This requires a high degree of trust between higher command and the boat.* Longer or higher priority messages – such as a change in mission – require satellite connectivity triggered by low frequency messages. Given that higher headquarters have little understanding of what that submarine might be doing means that the decision to break off from a mission and get into a position that allows the vessel to receive updates is a decision for the commanding officer of the submarine alone.

Conventionally powered submarines (SSKs) are electrically powered when submerged, recharging their batteries on or near the sea surface using diesel engines. Whilst the endurance on battery power has drastically improved, the demands of speed and life support can drain electrical power rapidly. SSKs usually operate better in littoral waters or in Direct Support roles, where the near-silence of electric engines makes them deadly adversaries. Given their requirement to ‘snorkel’ in order to recharge, communications with SSKs can generally be more frequent. However, it also requires a specialist set of skills to ensure they are employed effectively. Submarine tasking requires detailed knowledge of each boat, the captain and the crew, the geography (and oceanography) they are operating in, and the mission they are being set.

All this means that to be effective, submarines must operate with a degree of freedom unusual within modern militaries. Some may liken this to an extreme of mission command but it is beyond that strict definition. Optimised performance of submarines requires long periods without connectivity to higher commanders: that level of patience is increasingly rare amongst people from the ‘joint’ community obsessed with speed and data over results. How this will work in the future where ‘synchronisation’ becomes the driver for Western military operations is yet to be seen. Unlocking closer C2 and synchronisation with submarines (the seeming desire of military doctrine) requires advancing blue-laser in-water communications at low power; something that has vexed scientists for generations. Until then, and to maintain the submariners advantage in lethality-through-silence, better co-ordination requires a technical solution that enables low-bandwidth, high-precision situational awareness tools that can be accessed as necessary by a vessel thousands of miles from its homebase, and at a time selected by the captain – not the moment that higher commands deem worthy.

All of this requires people of the highest calibre, with the wit, cunning, ingenuity, and confidence to exercise their judgement in a sea of variables. Training and validating submariners from the lowest to the highest levels makes them some of the most precious assets in the national security community.

Most of all, submariners need to be allowed the freedoms to show their teeth: alone and unafraid in the world’s most treacherous and deadly domain.

*In naval parlance, ‘boat’ refers to submarines, ‘ship’ refers to floating vessels. ‘On board’ can refer to either.