Even by US military standards, the excitement surrounding Sea Hunter, a prototype unmanned submarine tracking vessel developed at a cost of $20m by US defence research agency DARPA, is startling. Variously described as “a highly autonomous unmanned ship that could revolutionise US maritime operations” and “a new vision of naval surface warfare”, the drone was developed through the agency’s Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ASW ACTUV) programme. (1)
‘revolutionize US maritime operations’
‘a new vision of naval surface warfare’
That’s some lofty praise and expectations for a vessel that has not yet demonstrated any capability, whatsoever.
Here are some of the claims being made for Sea Hunter:
-It has been described by the Navy as being capable of finding and following submarines indefinitely using a high frequency, fixed sonar array. (1)
-It has been suggested by observers as being capable of conducting complete, independent ASW operations.
-It has been suggested by commentators as being capable of conducting AAW/ASW wide area surveillance while, apparently, being undectectable.
“The drone boats could also scout well ahead of manned ships for the enemy… and get close to particularly high value assets, such as aircraft carriers or amphibious assault ships.” (1)
-It has been suggested as a replacement for capital ships.
“ACTUV represents a new vision of naval surface warfare that trades small numbers of very capable, high-value assets for large numbers of commoditized, simpler platforms that are more capable in the aggregate,” said Fred Kennedy, director of DARPA’s Tactical Technology Office (TTO). (1)
-It has been suggested as a mine countermeasures vessel and was tested in the role by DARPA. (1)
-It has been suggested as a harbor protection vessel.
-It has been suggested as a logistics supply vessel.
-It is planned to be used as an intel collection vessel.
… plans already in the pipeline include equipping drones with anti-submarine weapons and additional sensor suites to gather visual and electronic intelligence. (1)
As a refresher, the $20M Sea Hunter is a moderate size vessel (Medium Displacement Unmanned Surface Vessel, MDUSV) of 132 ft in length, capable of 27 kts, and was designed by DARPA to operate unmanned and autonomously. The vessel appears to be non-stealthy in the extreme. It is designed to be modular with regard to payloads. DARPA indicates the vessel can operate for 90 days with a range of 10,000 miles. (1)
DARPA has developed Sea Hunter, a prototype unmanned submarine tracking vessel with the ability to autonomously patrol the seas for months on end at a fraction of current costs. (1)
DARPA tested the Sea Hunter with the Towed Airborne Lift of Naval Systems (TALONS – a tortured, contrived acronym if ever there was one!) which is, essentially, a parasail carrying a sensor or communications package aloft via a cabled parasail. (1)
Operating costs are reported to be in the range of $15,000-$20,000 per day versus $700,000 per day for a destroyer. (1)
Sea Hunter was transferred from DARPA to the Office Of Naval Research (ONR) in early 2018.
So, there’s the background. Now how about some analysis?
ASW – The small size and low power of whatever sonar array the vessel has suggests a very limited sonar range. Also, the vessel has no helo which, on this blog, nearly every commentator has stated is mandatory for successful ASW (ComNavOps, of course, does not believe helos are mandatory for successful ASW – useful, yes; mandatory, no). Despite this, the Navy claims that the vessel, with a low powered, small sonar array and no helo, will be able to find and track submarines indefinitely despite that fact that our very best full size, high powered sonars on Burke destroyers, with the benefit of human interpretation of data and anticipation of submarine behavior and tactics and using helos to help search and prosecute, cannot reliably detect and track submarines. Does it really make sense to you that a $20M vessel with a small, low powered, unmanned sonar can outperform our Burkes? If that was really true and if that was what testing has already demonstrated (and I’m unaware of any realistic testing having been performed) wouldn’t the Navy be engaged in a crash program to replace the Burke sonars with these small, low powered sonars that require no manning and yet are many times more effective? And yet, they aren’t. What does that tell you?
Some commenters have suggested a swarm of Sea Hunters sweeping ahead of a surface group and clearing the path of submarines. Again, the very limited range of the sonar fit precludes any useful ASW sweep capability unless several dozen such vessels were employed and who is going to control and perform data analysis on several dozen vessels simultaneously?
Surveillance/Intel/Scouting – The small size and limited power again limit the range of whatever sensors might be placed on the vessel. More importantly, the vessel is non-stealthy, in the extreme, and would have a lifespan of minutes in a forward battle area. How anyone thinks this vessel will sail ahead of a surface group and survive long enough to collect any useful surveillance data is beyond me. Remember that to achieve any useful sensor range will require active radar which also pinpoints the craft’s location to the enemy.
Survivability – The vessel has no self-defense capability and is non-stealthy in the extreme. It’s lifespan will be measured in minutes in a battle zone.
Control – Unless these vessels are going to operate 100% autonomously – and no one believes we’re at that level of software capability – then someone has to control the vessels and analyze any data they collect. Given that most of the proffered applications call for many vessels, likely dozens, operating together, who is going to control the vessels and how will they do it? It will require continuous, wide area, two-way communications which doesn’t exactly fit with combat EMCON requirements.
Logistics – The use of a Sea Hunter as a logistics transport vessel is nearly pointless. It has no significant cargo capacity and no means to load/unload whatever it might carry.
Capital Ship Replacement – This is stupidity on a platter. Our surface fleet is already too small and steadily shrinking and we would replace what we have with these combat useless vessels? Claiming that the Sea Hunter is more capable in the aggregate is analogous to claiming that infantrymen are more capable in the aggregate than an armored unit of tanks. Infantry have their uses but they are not more capable than armored units.
Patrol – This is the one application that is potentially useful. Such a vessel might well make an efficient and effective harbor patrol craft. Of course, that’s a peripheral task rather than combat but it would still be useful if the vessel’s cost can be contained.
It is worth bearing in mind that for most of these suggested uses a MH-60R/S helo which costs about the same as Sea Hunter (helo costs are $28M-$42M depending on type and source) has much more mobility, speed, capability, and survivability than a Sea Hunter. In fact, the only redeeming quality of the Sea Hunter compared to a helo is the endurance and even that is only valid under certain defined circumstances. The helo’s endurance is unlimited in the sense that it is carried by a host ship and so can travel as far and as long as the host ship. The helos endurance becomes a factor only when it’s in the air – for example, dropping sonobuoys. In comparison, given the Sea Hunter’s utter lack of survivability, its endurance is likely to be a non-factor! All things considered for the helo vs. Sea Hunter, it almost seems as if we’re reinventing the wheel just to be able to make it unmanned.
Any reasonable analysis of Sea Hunter capability reveals the vessel to be very heavy on hype and very light on any useful function. As I’ve harped on so many times, this is what a CONOPS does – it lays out, in detail, how a vessel will be used. Sea Hunter has no CONOPS and, therefore, it can do anything and everything, or so its proponents would have us believe.
Sea Hunter, as it currently exists, is a hyped-up myth, nothing more. That’s not to say that it isn’t worthwhile as a research program. By all means, let’s continue to explore autonomy and unmanned vessels. However, the Navy has already committed to a fleet of these vessels (specifically, their small and medium displacement unmanned vessels) with absolutely no CONOPS and no idea of how to use them or what their capabilities are (hint to the Navy: I’ve just told you what their capabilities are; they don’t have any!). Does this sound eerily familiar? It should. It’s exactly what the Navy did with the LCS and you see how that turned out. Remember all the projected uses for the LCS? Why it was going to revolutionize the Navy and win wars single-handed. The reality is that they have no use, are a drain on resources, can’t seem to sail two days with a breakdown, require more manning than the Perrys they replace, and have no place in combat. It appears as if the Navy is now committed to building the unmanned version of the LCS. Well, no one ever accused the Navy of being able to learn lessons!
(1)Naval Technology website, “Sea Hunter: inside the US Navy’s autonomous submarine tracking vessel”, 3-May-2018,https://www.naval-technology.com/features/sea-hunter-inside-us-navys-autonomous-submarine-tracking-vessel/