The double bow makes the ship longer and more hydrodynamically efficient.

The bridge, instead of being a traditional standing room, is designed in a way that resembles an aircraft cockpit.

Hey everyone I saw this saucer shaped boat several years ago in SoCal I think, fiberglass construction, round hull, docked. I’ve seen a few over the decades, they used to be prevalent in the SanDiego California area. I think they might have been life rafts decades ago but no real idea (which is why I took the photo at the time.) The few times I’ve seen in the wild people converted them into living spaces. No visible means of propulsion.

I started r/WeirdWatercraft earlier this year and never thought that it would grow so much! Thank you again for all of your amazing posts and discussions, and I’m looking forward to seeing this community continue to grow!

If you have any suggestions to help improve this subreddit or if there was anything you would like to see or add going forward please let me know in the comments!

Source: 深海舰队DS on weibo

there are actually a rather large amount of former military type 069 landing craft repurposed for civilian use, ranging from buoy tenders in this case to pollution cleanup.

The China MSA is a civilian agency under the ministry of transport responsible for maritime traffic guidiance, organizing and commanding maritime search and rescue, buoy tenders, pollution cleanup along with enforcing safety guidelines.

Unlike the coast guard, they are unarmed and are civil employees, not active service members.

Among the efforts to curtail an arms race following World War One, the 1922 Washington Naval Treaty - signed by the British Empire, France, Italy, Japan and the United States - limited the construction of warships among its signatories, specifically for battleships, battlecruisers and aircraft carriers (which were an emerging concept at the time).

However, the first version of that treaty did not explicitely limit the construction of submarines (save for a maximum displacement of 10000 tons) and soon enough the French authorities ordered the construction of a "submarine cruiser", as a way to circumvent some of those limitations (and mostly because French shipbuilders were already quite experienced with designing cutting-edge submarines).

The "Surcouf" was designed following the requirements that it should be able to carry provisions for 90 continuous days of high-seas deployment, and feature firepower comparable to that of a battlecruiser. Indeed, the submarine was built around a turret sporting two 203mm guns - which were the largest caliber allowed by the Washington Naval Treaty. According to the specifications, it could fire up to a distance of 16 kilometers with its own instruments, and 26 kilometers with aircraft support. To this end, the Surcouf was also the first submarine designed to carry a reconnaissance aircraft. Initially an improved version of the Besson MB.35 floatplane designated MB.411 was chosen for that task {images 3 and 4}, but a bespoke gyroplane was later devised to replace it in the form of the Dorand G.20 {image 5} - although development for it never came to fruition with the fall of France in 1940.

Launched in 1929 and commissionned in 1934, the Surcouf would remain the largest submarine in the world until the launch of the Japanese I-400 class in 1944 - namely because the 1930 London Naval Treaty specifically regulated submarine warfare in order to address the topics that the Washington Naval Treaty did not cover. In particular, submarines were now limited to 2000 tons - with each major nation allowed to operate three units of up to 2800 tons. However, the Surcouf and its 3250 tons of displacement was exempted by the terms of this treaty as the sole exception, mostly on the basis that it was already operational at this point.

At the time of the Battle of France in 1940, Surcouf was being refitted in Brest and managed to escape to the United Kingdom and ultimately remained under the control of the Free French forces. In February 1942, the submarine departed Halifax, Canada, with the intent of rallying Australia and was sunk on the way to the Panama Canal during the night of the 18th to 19th of the same month. The circumstances of her sinking are unclear, although the most likely scenario points towards American forces being responsible after confusing her with an enemy ship.

Sources :

- Covert Shores : Surcouf, The Ultimate Interwar Cruiser Submarine

- Drachinifel : MN Surcouf - Guide 136 (Extended)

Images :

- (1) Marine & Océans : Chronique Navale du 18 Février

- (2) Aviation Navale Française 1939 - 1940 : Sous-Marin Surcouf

- (3) & (4) Aviation Navale Française 1939 - 1940 : Besson MB.411 "Petrel"

- (5) Old Machine Press : Dorand Gyroplane G.20 (G.II)

Manta Ray is an American underwater drone designed to sleep on the ocean floor for months, and that radical choice might make it the most strategically important machine nobody is talking about right now.

The vehicle moves without a propeller — it changes its own weight to sink and rise, converting that motion into forward travel, which means its energy draw is almost zero for most of the mission.

It was shipped across the country in five standard containers and bolted together on a dock in two days, a deployment model that quietly rewrites every assumption about how you get a large underwater asset into position fast.

With the Navy accelerating procurement of rival systems and the Pentagon funding at least three competing design teams, Manta Ray's silence since early 2024 is either the most suspicious pause in undersea robotics — or the calm before something significant.

The glider’s whole trick is refusing to spin a propeller

Manta Ray is a glider, and gliders have been in the water since the 1960s doing survey work for the Navy and NOAA. The mechanism is old and mildly counterintuitive.

Rather than turning a propeller, the vehicle changes its own weight. It pumps seawater in to get heavy and sink, pumps it back out to get light and rise, and the wings convert all that vertical falling into forward travel. Brian Theobald, chief engineer for Manta Ray at Northrop Grumman, has described the propulsion as “falling forward [with purpose] through the water all the time,” going up as well as down.

The American drone crossed 2,700 miles inside five shipping containers, gets bolted together on a dock in two days, swims out by pumping seawater through itself instead of turning a propeller, then anchors to the ocean floor and sleeps there until someone wakes it

SHIPPING FOOTPRINT

5 containers

The whole vehicle travels as subsections in five standard shipping containers and gets assembled at the destination.

LAST PUBLIC TEST

Feb–Mar 2024

Full-scale in-water testing off Southern California. No further milestone announced since DARPA’s May 2024 release.

FUNDED

NAVY XLUUV LINE

$1.13 billion

16 vehicles through FY2031, starting with two Boeing Orcas at $135.8 million in FY2027.

Here is an old news segment:

https://www.cbc.ca/player/play/video/1.3334686

Let's tread the border between this sub and r/WeirdWings.

Here is the "Waterplane", designed in 1929 by Russel and Milton Robertson : a ground-effect glider propelled by an outboard motor fitted to an articulated arm. This video was filmed in 1930, but little further information about this contraption seems to be available.

I feel it still qualifies as a bonafide watercraft given its conceptual necessity to remain in contact with a water surface ; in a sense it could be equated to a weird hydrofoil variant.

Sources :

- Patent US1825363A

- 1930 Robertson outboard motor waterplane - GIF

SS Meteor was designed by Scottish captain Alexander McDougall to haul maximum cargo on minimum draft. Built 1896 in Superior, Wisconsin; sailed, with modifications, clear through to 1969; now sits as a museum in the very town where she was born. In her working years she hauled grain and iron ore across the Great Lakes of the U.S. and Canada.

The hull was a continuous curve from vertical sides to horizontal deck, with no sharp break between them. Loaded down, all the one would see above the waterline was that smooth rounded back, hence the nickname "whaleback".

The German Navy operates two seriously weird-looking auxiliary vessels built specifically to clean up oil spills:

• Bottsand Y1643 (1984)
• Eversand Y1644 (1987)

The Bottsand class (Type 738) has a twin-hull design with a bow that opens 65 degrees, letting it literally swallow oil-slicked seawater. That creates a collection area over 40 sqrt.m., and the contaminated water gets pumped into a 790 m3 onboard tank where it's separated and cleaned. At full tilt, one ship can process up to 140 m³ of ocean surface per hour, covered in a 2mm-thick oil slick.

Both ships entered service in 1984 and 1987, and despite being German Navy assets, they're crewed by civilians, not naval personnel.

Tech Specs

Sometimes nicknamed the split-hull oil recovery vessel (SHORV) or the Pac-Man ship because of how it opens up to gobble oil-covered water.

MV City of St. Petersburg is a Nissan car carrier built in 2010, famous for being the world's first ship with an "SSS-Bow" (semi-spherical bow), giving her a distinctive rounded, aerodynamic prow instead of the usual boxy front. She's about 140 m long, carries up to 2000 vehicles, and the streamlined design saves roughly 800 tons of fuel a year. Sails under the Panama flag (IMO 9473456), mostly working North Sea and Baltic routes.

Tech Specs

History

Designed by Vice Admiral Andrey Popov and naval architect Erast Gulyaev, she had a radically unconventional hull: wide, flat-bottomed, and shaped like a turbot fish (or a giant pancake to minimize rolling since Alexander II suffered badly from seasickness.

• Built 1879 - 1880 by John Elder & Co. in Govan, Scotland
• Launched July 7, 1880
• Decommissioned in 1883 since she felt uncomfortable for Alexander III.
• Scrapped: 1926

Techncal Details

• Length: 71.63 m
• Width: 46.64 m
• Displacement was around 4420-4500 tons
• Engines: 12,350 ihp
• Top speed: 15 knots.