HMS Stubborn Submarine Wreck

Site Profile

The only submarine you can dive in Malta without a UCHU permit.

1941

HMS Stubborn (P238) was laid down at Cammell Laird & Co, Birkenhead in December 1941, launched April 1942, and commissioned into the Royal Navy in February 1943 as part of the S-class submarine programme. She measured 66 metres in length and was armed with six torpedo tubes at the bow and one at the stern.
1943

Stubborn served in the North Atlantic and Arctic theatres during the Second World War, conducting offensive patrols against German and Italian naval targets. In February 1943 she survived a severe depth-charge attack off the coast of Norway that caused significant structural damage, requiring major repairs at her home port before returning to active service.
1945

With the war over, Stubborn was placed in reserve as part of the post-war drawdown of the Royal Navy's submarine fleet. The vessel was stripped of sensitive equipment and armaments before being allocated for disposal.
1946

On 30 April 1946, HMS Stubborn was deliberately scuttled 3 kilometres northeast of Qawra Point, Malta. She came to rest upright on the sandy seabed with a slight starboard tilt, her hull substantially intact between 45 and 56 metres.
Today

The Stubborn is the only submarine wreck in Maltese waters that can be dived without a permit from the Underwater Cultural Heritage Unit (UCHU). The conning tower, external torpedo tubes, hydroplanes, and pressure hull are all in recognisable condition. She is accessible only by boat and only to divers holding a recognised technical diving certification.

Eighty years on the seabed have left HMS Stubborn in remarkable condition. Unlike every other wreck in Maltese waters, the Stubborn can be dived without a permit from the Underwater Cultural Heritage Unit (UCHU), making it the most accessible technical wreck dive on the islands. The pressure hull remains largely intact in profile, the conning tower stands proud of the casing, and the twin hydroplanes are clearly identifiable from above. The external torpedo tube doors at the bow are still present, marking this unmistakably as a submarine built for war. Bottom time at this depth is severely limited and must be planned with precision. diveshack guides with full technical configuration experience run all Stubborn dives under strict gas and decompression protocols. No part of this dive is improvised.

// Depth Profile · HMS Stubborn P238 · S-Class Submarine

Points of Interest

One submarine. Four defining features.

At this depth, bottom time is measured in minutes. Each feature rewards a focused, pre-planned approach. Decide what you are going to look at before you descend and stick to the plan.

CONNING TOWER · 45m

45m

Tec Zone · Midship

Conning Tower

The conning tower is the centrepiece of the dive and the first structure encountered after descending the shot line. Rising approximately three metres above the pressure hull casing, it stands in remarkable condition. The bridge rails, access hatch coaming, and periscope standards are all identifiable without penetrating the structure. At this depth, ambient light is muted but in summer visibility allows the full silhouette to be seen in context, the 66-metre hull stretching away from the tower in both directions. This is unlike any recreational wreck in Malta.

// Descend shot line direct to tower · Do not penetrate · 5 min max at depth

TORPEDO TUBES · 48m

48m

Tec Zone · Bow

External Torpedo Tubes

The bow of HMS Stubborn carries the external torpedo tube doors as fitted during her wartime service. Three circular tube openings are clearly visible at the bow, still aligned as they were when the submarine was in commission. This is the feature that most powerfully communicates the vessel's wartime purpose. Approaching the bow requires moving forward from the conning tower along the casing to around 48 metres. The tube doors are partially open on the port side, giving a direct view into the bore. Plan this as the deepest point of your dive and visit it first.

// Plan as deepest point · Visit first to maximise NDL · Watch gas

PRESSURE HULL · 45–56m

45–56m

Tec Zone · Full Length

Pressure Hull

The pressure hull of an S-class submarine is a double-skin construction, and on the Stubborn this is clearly readable as you move along the vessel's flank. The outer free-flooding hull carries considerable encrustation at this depth, sponge colonies and invertebrate communities that have had eight decades to establish. The circular cross-section narrows toward the stern, which sits at the deepest point of the wreck at 56 metres. Looking along the full length of the hull from the conning tower in good visibility gives a genuine sense of the vessel's 66-metre span: uncommon at any depth in Malta.

// Stern at 56m · Plan deco before descending · Do not penetrate

HYDROPLANES · 45m

45m

Tec Zone · Bow & Stern

Hydroplanes

Both pairs of hydroplanes are present and intact. The forward planes are positioned just aft of the torpedo tubes and project clearly from either side of the hull. The after planes are located at the stern near the rudder and are visible alongside the propeller and rudder assembly. On an S-class submarine, the fore hydroplanes controlled depth during diving and surfacing, and seeing them extended and in position at 45 metres on a vessel that last submerged under her own power in 1946 has a quality that words do not quite reach. The rudder, propeller shaft, and four-bladed propeller complete the stern picture.

// Best viewed from directly above the hull · Do not touch the growth

Diving Conditions

When and how to dive it.

The Stubborn is diveable year-round in settled weather. Summer and early autumn give the best conditions overall. This is an open water boat dive at technical depth: weather windows and sea state matter as much as visibility.

Season	Visibility	Temp	Rating
Jan – Mar	10–18m	14–16°C	Fair
Apr – Jun	15–22m	17–22°C	Good
Jul – Sep	20–25m	24–26°C	Peak
Oct – Dec	18–24m	20–24°C	Peak

Average Visibility at Depth

Jul – Sep

22m

Oct – Dec

20m

Apr – Jun

17m

Jan – Mar

13m

Visibility at Depth

Open water 3km offshore means no harbour silt or reef particulate to degrade clarity. In summer, 20 metres or more of horizontal visibility is common at the wreck. In winter and early spring, thermoclines can reduce mid-water visibility before improving again closer to the bottom. Even at 15 metres visibility, the full length of the submarine is readable from the conning tower. This is one of the cleaner sites in Malta for a wreck at this depth.

Boat Access & Descent

Boat departure from Qawra or St Paul's Bay depending on conditions. A shot line is deployed directly to the conning tower at 45 metres. All divers descend and ascend the shot line. Open water conditions mean swell and surface chop can affect entry and exit. DSMB deployment at depth is required from every diver before the final ascent. The dive boat holds position above the shot line throughout the dive.

Current

A mild to moderate northeasterly current runs across this site. At the wreck depth it rarely exceeds 0.5 knots, but the surface current can be noticeably stronger and is assessed before shot deployment. Strong northerly or easterly weather increases surface movement considerably. Dives are called off when sea state exceeds Beaufort 3 or when the guide judges conditions unsafe for open water technical diving. No exceptions are made for this site.

Safety & Requirements

Technical cert is not optional here.

HMS Stubborn starts at 45 metres and reaches 56 metres at the stern. No-decompression limits on air at this depth are measured in single-digit minutes. This is not a deep recreational dive with extra paperwork. It is a full technical dive and diveshack will not take undercertified divers to this site under any circumstances. Cert cards are checked at the boat before departure, every time.

TEC

Technical Certification: Mandatory

A recognised technical diving certification is the absolute minimum to dive HMS Stubborn. SSI Tec 45, SSI Tec 65, PADI Tec 45, PADI Tec 65, BSAC with relevant technical endorsement, or equivalent agency qualification. Advanced Open Water, Deep Specialty, and Rescue Diver certifications do not qualify for this site. No exceptions, no upgrades on the day, no waivers. If you are interested in the site but hold only recreational certification, ask us about our SSI technical training pathway.

Tec certification mandatory

NDL

Decompression Planning

At 56 metres on air, the no-decompression limit is approximately 5 minutes. At 45 metres on air it extends to around 8 minutes. All diveshack Stubborn dives are conducted on nitrox or trimix with planned decompression stops built into the dive profile. A minimum of one staged decompression stop at 6 metres is required on every dive. Gas planning follows strict rule-of-thirds protocol. Bailout cylinder carriage is assessed per diver and is mandatory for certain equipment configurations.

Deco planned: minimum 6m stop

DSMB

DSMB: Non-Negotiable

This is an open water boat dive 3 kilometres from shore. There is no surface reference, no fixed ascent line, and no shore to swim to. Every diver must carry a delayed surface marker buoy and must be able to deploy it confidently at depth while managing a decompression obligation. DSMB deployment competency is assessed during the pre-dive briefing on the boat. Divers who cannot demonstrate the skill will not be cleared to enter the water. Surface signalling is the only way to locate a separated diver out here.

DSMB mandatory for every diver

Gas

Gas Configuration

Minimum starting pressure of 220 bar. Twin-cylinder manifold configuration is strongly recommended for all divers on this site. Single-cylinder entry is accepted only where the diver carries a staged bailout. Nitrox EAN32 is available through diveshack and should be booked with the dive. Trimix is available on request for divers planning maximum depth excursions to the stern section. All cylinders are inspected and analysed before the boat departs.

Nitrox standard · Trimix on request

Brief

Pre-Dive Briefing

A full technical briefing is conducted at the dive centre before departure and repeated on the boat at the site. The briefing covers: planned maximum depth, turn-around pressure, staged decompression schedule, lost diver procedure, DSMB deployment sequence, surface signals, emergency ascent protocol, and the location of the nearest hyperbaric facility. All divers sign the briefing acknowledgement. Maximum group size is four divers per technical guide, and this limit is firm.

Max 5 divers per technical guide

DAN

Emergency Provision

Nearest hyperbaric chamber at Mater Dei Hospital, Msida. Emergency oxygen available on the dive boat throughout. DAN dive accident insurance is strongly recommended and is available to arrange through diveshack. Emergency: 112. DAN Europe: +39 06 4211 5685. All technical guides hold oxygen provider and first-aid certifications. The hyperbaric emergency protocol is covered in every pre-dive briefing for this site.

DAN insurance available

Book This Dive

Dive HMS Stubborn with diveshack

Technical dives to HMS Stubborn run by arrangement on settled days. Departure from Qawra or St Paul's Bay at 08:00. All divers must present valid technical certification before departure is confirmed. Private technical charters available with advance notice. Minimum booking: 2 qualified technical divers.

Departs 08:00, by arrangement, Qawra / St Paul's Bay

Duration Approx. 3 hours total including decompression

Group Size Max 5 divers per technical guide

Cert. Required Technical cert mandatory (SSI/PADI Tec 45 minimum)

Gas Nitrox EAN32 standard, trimix on request

Equipment DSMB required, technical configuration mandatory

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Additional Notes

We respond within 2 hours, 08:00–17:00 Malta time. Tec cert verification required before booking is confirmed.

HMS Stubborn

The only submarine you can dive in Malta without a UCHU permit.

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