{{Short description|Twin screw boat}} {{Use dmy dates|date=December 2016}} {{Use British English|date=December 2016}} {{Infobox ship |sclass=2 |section1={{Infobox ship/image |image=260422 351 SMB-03 Rosneath Point, Rhu marina.jpg |image_caption= SMB-03 (Sea class 15 m with survey module) }}
|section2={{Infobox ship/class overview |name=Sea class |builders= |operators={{flagicon|United Kingdom|naval}} Royal Navy |class_before= |class_after= |built_range=2017–2024 |in_service_range=2018–present |total_ships_completed=35 + 7 (Arcims-class) minehunting variants |total_ships_canceled= |total_ships_active=35 + 7 |total_ships_laid_up= |total_ships_lost= |total_ships_retired= |total_ships_preserved= }}
|section3={{Infobox ship/characteristics |hide_header= |header_caption= |type=Workboat/training/diver support/survey/minehunting vessels |tonnage= |displacement={{cvt|15|to|23|t|LT}} (11-15 m Workboat variants); {{cvt|37|t|LT}} (HMS ''Magpie'') |length=* {{cvt|11|m|ftin}} *{{cvt|13.8|m|ftin}} *{{cvt|15|m|ftin}} *{{cvt|18|m|ftin}} |beam= |height= |draught= |draft= |power= |propulsion=Yanmar diesels; twin waterjets |speed=up to {{convert|40|kn}}<ref>{{Cite web |title=SEA Class Marine Craft |url=https://www.atlas-elektronik.com/solutions/surface-vessel-systems/sea-class-marine-craft.html |website=Atlas Elektronik |access-date=18 June 2024}}</ref><ref>{{Cite web |title=Influx of new birds on the Dart spurs on naval leaders of tomorrow |url=https://www.royalnavy.mod.uk/news/2025/march/28/2250328-influx-of-new-birds-on-the-dart-spurs-on-naval-leaders-of-tomorrow |website=Royal Navy |date=30 March 2025}}</ref> |range= |endurance= |boats= Remus UUV (11, 15 & 18 m survey modules);<ref>{{Cite web |title=Royal Navy procures the latest generation REMUS 100 UUVs|url=https://www.navalnews.com/naval-news/2022/09/royal-navy-procures-the-latest-generation-remus-100-uuvs/ |website=Naval News |date=21 September 2022}}</ref> SeaCat UUVs (Arcims-class variants)<ref>{{Cite web |title=Royal Navy autonomous mine hunting at the sharp end |url=https://www.navylookout.com/royal-navy-autonomous-mine-hunting-at-the-sharp-end/ |website=Navy Lookout |date=30 March 2023}}</ref> |capacity= |troops= |complement= 2 berths (11 m variants), 4 berths (13.8 & 15 m variants), up to 9 crew (HMS ''Magpie''); up to 36 passengers (13.8 m variant); up to 12 cadets (15 m officer training variants) |notes= }} }}
The '''Sea-class workboat''' has been procured for Britain's Royal Navy to undertake a number of roles under its ''Project Vahana'' programme, with removable specialised modules including: logistics and transport tasks, inshore and harbour survey work, diver training and support, officer training and providing passenger transfer modules for the aircraft carrier {{HMS|Prince of Wales|R09|6}}. The design was developed from an autonomous minehunting prototype which has also been procured, becoming part of the class.
A procurement contract for £48M was awarded to Atlas Elektronik UK (AEUK) in September 2017 for the delivery of up to 38 vessels under the programme. Thirty-five vessels were ultimately built, with deliveries beginning in 2018 and completing in 2024. Only {{HMS|Magpie|H130|6}} (the largest boat in the series) is formally a commissioned warship of the Navy. The remaining boats are not technically commissioned warships.<ref>{{Cite web |url=https://www.navylookout.com/in-focus-the-versatile-new-workboats-being-built-for-the-royal-navy/ |title=In focus: the versatile new workboats being built for the Royal Navy |website=Navy Lookout |date=6 August 2018}}</ref>
==Developmemt== Remote controlled minesweeping was not a new idea; in 2003 during Operation Telic in Iraq. Atlas Elektronik UK Ltd developed their ARCIMS (Atlas Remote Capability Integrated Mission Suite) mission system which has several coil auxiliary boats (CABs), to emit signals detonating mines, towed behind an autonomous unmanned surface vessel (USV). The system was demonstrated successfully at DSEI 2013, using a purpose built 11 metre USV (which was later named ''Hussar'') and two systems were exported to an overseas navy. In May 2015 Atlas were awarded a £13 million MOD contract to supply this autonomous minesweeping capability, including four USVs, to the Royal Navy, in partnership with Babcock, to be integrated by BAE SYSTEMS with their NAUTIS command system.<ref name="awarded 150528" /><ref name="unmanned 180505">{{cite web|title=The Royal Navy gets its first unmanned minesweeping system|website=Navy Lookout - Independent Royal Navy news and analysis|date=5 May 2018|url=https://www.navylookout.com/the-royal-navy-gets-its-first-unmanned-minesweeping-system/|access-date=21 May 2026}}</ref> thumb|left|RNMB ''Hussar'' on the Clyde in 2019 The navy planned ''Project Vahana'' to replace small vessels with a unified system, and in September 2017 announced that Atlas Elektronik UK (AEUK) had won this £48M contract for up to 38 SEA class vessels, fully fitted out with a standard hull form (derived from the ARCIMS design) in 11m, 13m, and 15m lengths, and mission equipment modu[es, which can be interchanged. In addition, the 18m launch HMS ''Magpie'' was built by another shipyard to a proven design, then fitted out by Atlas with survey modules.<ref name="focus 180806">{{cite web|title=In focus: the versatile new workboats being built for the Royal Navy|website=Navy Lookout - Independent Royal Navy news and analysis|date=6 August 2018|url=https://www.navylookout.com/in-focus-the-versatile-new-workboats-being-built-for-the-royal-navy/|access-date=21 May 2026}}</ref> Atlas Elektronik delivered the ARCIMS system together with the first tested autonomous vessel, RNMB ''Hussar'', and a manned version named RNMB ''Hazard''. After successful trials off Dorset, they were handed over to the Royal Navy at the start of May 2018, as was HMS ''Magpie''.<ref name="awarded 150528">{{cite web|title=Atlas Elektronik UK awarded UK MoD Autonomous Minesweeping Capability|website=Defense News security global military army equipment industry|date=28 May 2015|url=https://www.armyrecognition.com/archives/archives-naval-defense/naval-defense-2015/atlas-elektronik-uk-awarded-uk-mod-autonomous-minesweeping-capability-contract|access-date=21 May 2026|quote=the naval demonstration at DSEI 2013 ... The ARCIMS mission system (based on a specially designed 11 metre vessel) can be transported easily by road, rail or military aircraft.}}</ref>
==Vessel types and roles== thumb|right|HMS ''Magpie'' (Sea class 18 m variant) The Sea-class workboat has standard hulls with modules that are interchangeable, allowing the vessels to adapted for different tasks. As initially acquired, the class includes several variants:
* 10 × 11 m standard workboats for transport and logistics tasks; * 3 × 11 m small survey modules assigned to the Hydrographic Exploitation Group based out of HMNB Devonport; * 3 × 13.8 m passenger transfer modules (assigned to HMS Prince of Wales); * 18 × 15 m workboats for officer training, diver training/support and survey/hydrography duties; and, * 1 × 18 m inshore survey unit (HMS ''Magpie'').
Eight 15-metre officer training vessels are assigned to the Britannia Royal Naval College,<ref>{{cite web |title=Up close with the Royal Navy’s new officer training boats |url=https://www.navylookout.com/up-close-with-the-royal-navys-new-officer-training-boat/ |access-date=31 May 2024 |website=Navy Lookout |date=27 September 2021}}</ref> while the six 15-metre diver training and support vessels are assigned to HMNB Portsmouth (three units), HMNB Devonport, HMNB Clyde and to the Royal Navy's Gibraltar Squadron (one unit each). Three of the 15-metre vessels are configured for survey/hydrographic work, with one of the vessels (''Salamander'') being based with the Hydrographic Exploitation Group in HMNB Devonport.<ref>{{Cite web |url=https://des.mod.uk/vahana-boats-atlas-royal-navy/ |title=Final Vahana Workboats delivered to complete Royal Navy fleet |website=Ministry of Defence |date=19 July 2024}}</ref><ref>{{cite news |title=The final of six new boats to improve support to Royal Navy divers has been delivered |url=https://www.royalnavy.mod.uk/news-and-latest-activity/news/2023/february/23/230127-diving-support-boat |access-date=3 July 2023 |publisher=Royal Navy |date=23 February 2023}}</ref><ref>{{cite news |title=ATLAS ELEKTRONIK UK SEA Class – Delivering an Innovative, Flexible, Cost-effective Solution to the UK MOD |url=https://www.thyssenkrupp-marinesystems.com/en/teaser/atlas-elektronik-uk-sea-class |access-date=11 March 2023 |publisher=Thyssen-Krupp Marine Systems }}</ref>
The vessels have been constructed to be fully compatible with AEUK’s autonomy engine enabling an unmanned capability to be integrated as a future need arises.<ref>{{cite news |title=Royal Navy: Advanced Vahana SEA-class boats all built – ships set to support HMS Prince of Wales and UK fleet |url=https://www.portsmouth.co.uk/news/defence/royal-navy-advanced-vahana-sea-class-boats-all-built-ships-set-to-support-hms-prince-of-wales-and-uk-fleet-4709528 |access-date=23 July 2024 |newspaper=The News |last=Webb |first=Freddie |date=19 July 2024}}</ref>
===Autonomous minehunting/sweeping=== left|thumb|RNMB ''Harrier'' (Arcims-class)
A specifically-focused autonomous minehunting vessel, also produced by Atlas Elektronik, preceded the class (being identified by the Navy as the ''Arcims''-class).<ref>{{cite web |title=Autonomous minehunting test team mark one year in the Gulf |url=https://www.royalnavy.mod.uk/news-and-latest-activity/news/2024/march/13/240313-harrier-in-the-gulf |access-date=12 June 2024 |publisher=Royal Navy |date=13 March 2024}}</ref> Six 11-metre variants of the type (RNMBs ''Hussar'', ''Hazard'', ''Halcyon'', ''Harrier'', ''Hellcat'' and ''Hydra'') were acquired by the Royal Navy and assigned to the Mine Threat and Exploitation Group at HMNB Clyde. The vessels have been procured under the Mine Hydrographic Capability (MHC) programme and are fitted with acoustic, electronic, and magnetic payloads that can emit signals through two or three towed craft (Coil Auxiliary Boats (CABs)) to trigger mines into thinking that a target ship is passing by.<ref>{{Cite web |title=Beating the Minefield with Autonomous Countermeasures |url=https://issuu.com/vishmeh/docs/arm_2212_2301/s/24697925 |website=Issuu |last=Fish |first=Tim |date=December 2022}}</ref> The boats can operate crewed, be remotely controlled or be pre-programmed to conduct missions autonomously.<ref>{{Cite web |title=Royal Navy autonomous mine hunting at the sharp end |url=https://www.navylookout.com/royal-navy-autonomous-mine-hunting-at-the-sharp-end/ |website=Navy Lookout |date=30 March 2023}}</ref><ref>{{cite news |title=ATLAS ELEKTRONIK UK SEA Class – Delivering an Innovative, Flexible, Cost-effective Solution to the UK MOD |url=https://www.thyssenkrupp-marinesystems.com/en/teaser/atlas-elektronik-uk-sea-class |access-date=11 March 2023 |website=Thyssen-Krupp Marine Systems }}</ref> The 11 m boats can be transported on either the RAF's A400M or C-17 transport aircraft.<ref>{{Cite web |title=Royal Navy autonomous mine hunting at the sharp end |url=https://www.navylookout.com/royal-navy-autonomous-mine-hunting-at-the-sharp-end/ |website=Navy Lookout |date=30 March 2023}}</ref> In 2025, three sets of this autonomous minesweeping capability (known as SWEEP) were officially incorporated into the Royal Navy's capabilities. Four vessels (''Halcyon'', ''Hussar'', ''Hydra'' and ''Harrier'') were enabled for autonomous/uncrewed operations.<ref>{{Cite web |title=Royal Navy brings mine sweeping back into the fleet|url=https://www.navalnews.com/event-news/dsei-uk-2025/2025/09/royal-navy-brings-mine-sweeping-back-into-the-fleet/ |website=Naval News |date=12 September 2025 |access-date=13 September 2025 |last=Scott |first=Richard}}</ref> The other vessels have been employed as crewed workboats for route surveys in the U.K. and elsewhere, as well as for trials of small uncrewed underwater vehicles (UUVs).<ref>{{Cite web |title=TKMS Atlas completes deliveries of 3 SWEEP systems for the Royal Navy Mine CounterMeasures capability|url=https://www.fw-mag.com/shownews/632/tkms-atlas-completes-deliveries-of-3-sweep-systems-for-the-royal-navy-mine-countermeasures-capability |website=Future Warfare Magazine |date=16 July 2025 |last=Molinelli |first=Gabriele }}</ref><ref>{{Cite web |title=In focus: Royal Navy minesweeping capability restored|url=https://www.navylookout.com/in-focus-royal-navy-minesweeping-capability-restored/ |website=Navy Lookout |date=29 July 2025}}</ref>
An additional 15-metre minehunting variant (RNMB ''Hebe'') was also procured and similarly assigned to the Clyde naval base. The greater size of ''Hebe'' permits her to accommodate a Portable Operations Centre Afloat that allows her to control her sister vessels while also coordinating autonomous operations.<ref>{{Cite web|url=https://www.royalnavy.mod.uk/news-and-latest-activity/news/2020/august/21/20200821-future-mine-hunting-system-comes-to-clyde|title=Future mine hunting system comes to Clyde |publisher=Royal Navy |date=21 August 2020}}</ref>
In 2023, RNMB ''Harrier'' was tasked to undertake trials with the Royal Navy's 9th Mine Counter-Measures Squadron based at {{HMS|Jufair}} in Bahrain. It is planned that autonomous minehunters, operating from command "mother ships", will incrementally supersede crewed minehunters operated by the Royal Navy.<ref>{{Cite web |title=Royal Navy autonomous mine hunting at the sharp end |url=https://www.navylookout.com/royal-navy-autonomous-mine-hunting-at-the-sharp-end/ |website=Navy Lookout |date=30 March 2023}}</ref><ref>{{Cite web |title=Up close with RFA Stirling Castle – first of the navy’s new motherships |url=https://www.navylookout.com/up-close-with-rfa-stirling-castle-first-of-the-navys-new-motherships/#:~:text=Force%20protection%20weapons%20have%20not,be%20added%20in%20the%20future |website=Navy Lookout |date=4 July 2023}}</ref>
==See also== * {{sclass|Archer|patrol vessel|1}} * {{sclass2|P1000|picket boat|1}} * Patrol Craft Fast - the "Swift Boats" * {{sclass|Cutlass|patrol vessel|1}}
==References== {{reflist}}
Category:Auxiliary ships of the Royal Navy