Military Review

Unobtrusive boats SEALION and Alligator

The US command of special operations forces USSOCOM tested various "invisible boats" for use by reconnaissance and sabotage units and special forces of the US Navy. Although these tests were carefully hidden, over the years several boats were still spotted by onlookers. Recently, USSOCOM began the commissioning process of semi-submersible "invisible boats" of the SEALION family, attributing them to the category of a heavy combat boat CCH (Combatant Craft Heavy).

Unobtrusive boats SEALION and Alligator

Alligator class

The first boat, currently known as the Alligator class, was made no earlier than the middle of the 90-s, and its design was later significantly improved. After testing by the US military Alligator boat was transferred to the Israeli military.

Displacement: 23,4 tons
Maximum speed: 30 nodes (8 underwater)
Length: 19,81 m
Width: 3,96 m


A small company, Oregon Iron Works, designed and built a series of boats for sabotage forces that are currently used by Israeli Navy special forces and US Navy special forces. The original patents were granted in 1990, and they may well have been influenced by Italian submersibles. Illustrations from the patent 1993 year:

Heavy fighting boat SEALION (I and II) CCH

Following the Alligator class was followed by the Sealion class (SEAL Insertion, Observation and Neutralization - the introduction of observation and neutralization, maritime special forces), which was designed for the introduction and withdrawal of special forces in a complex combat situation. It was designed on the basis of Oregon Iron Work's proprietary technology in collaboration with the department of combat vessels of the US Navy's surface weapons development center.

SEALION-I was delivered in January of the 2003 of the year and, together with the improved model of the SEALION-II, passed advanced tests of the naval special forces to the 2013 of the year. The cost of the program was approximately 10 million dollars. In 2013, the two hulls were upgraded and refined to full operational readiness. The Sealion boat is slightly longer than the Alligator, has a larger aft cockpit that can accept two rigid-hull inflatable boats of the RHIB type. After folding the masts in the special compartments, hydrocycles and underwater vehicles for the transportation of divers can be transported.

Semi-submersible boat class Alligator Israeli Navy

The new stealth boat was built by Oregon Iron Works in 2013 and later entered service with the Israeli fleet, mainly as a replacement for the original Alligator.

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  1. corporal
    corporal April 13 2016 07: 21
    Not a specialist in radar, but the question arose: "If radars detect the snorkel of submarines, won't they see a boat, albeit a semi-submersible one?"
    Yes, and different hydrophones near strategic sites, for sure that is still a headache for combat swimmers.
    1. Jack-b
      Jack-b April 13 2016 07: 32
      As a nonsense nespetsu))) as far as I heard, periscopes are detected, but at a very short distance, several kilometers. Much less torpedo attack distance. In the sea and ocean, these are very small distances. These boats will be detected a little further.
      1. 17085
        17085 April 13 2016 08: 26
        Very often, waves from wooden boats are easier to spot on the radar than the boats themselves. Of course it depends on the weather ...
        1. Arh
          Arh April 13 2016 09: 23
          I really wanted our innovations in such matters ...
          1. Izotovp
            Izotovp April 13 2016 20: 15
    2. Alex_59
      Alex_59 April 13 2016 08: 34
      Quote: Corporal
      Not a specialist in radar, but the question arose: "If radars detect the snorkel of submarines, won't they see a boat, albeit a semi-submersible one?"

      Anything can be noted, the question is only at what distance and with what radiation power. The level of the radar signal reflected from the subject depends on the area of ​​the subject, and on the distance to the subject depends to the fourth degree, well, on the radiated power. Therefore, the snorkel, as an object having a very small area, is detected by the same radar at a much smaller distance than the same radar will be detected by the boat. Or at the same distance, but to detect the snorkel, it will take several times more radiated power.
      1. Foofighter
        Foofighter April 13 2016 08: 58
        Karinka was not painted by an Englishman, the ballast is always below. bully
        1. Verdun
          Verdun April 13 2016 11: 28
          Boats, like larger ships, are often equipped with airborne ballast tanks. They take sea water to reduce roll or pitching.
          1. Foofighter
            Foofighter April 14 2016 10: 31
            it's not ballast, especially in english
      2. The comment was deleted.
      3. Izotovp
        Izotovp April 13 2016 20: 18
        I think that in the process of developing a submarine for the Huska project, where the use of composites in cladding is announced, something will go to other projects)))
    3. Starover_Z
      Starover_Z April 13 2016 09: 41
      Nice boat! Should be, judging by the high-speed contours, but 30 knots in total ?!
      And couldn’t attach hydrofoils to get to the destination faster on the surface?
      And the hull has a smaller area in the water and the wave from it is smaller, no?
      1. Come on
        Come on April 15 2016 04: 32
        30 knots in total ?! Not so little if stealth remains with them. Yes, and surface wings, then why should his coast guard notice from afar? :))
  2. Verdun
    Verdun April 13 2016 10: 34
    To fight terrorists or drug dealers somewhere in Panama is fine. And against serious means of detection - it is doubtful. Boats, apparently, are fast. And this means that they are noisy and leave behind a strong wave footprint. From this point of view, underwater vehicles are preferable.
  3. Operator
    Operator April 13 2016 16: 22
    How many tens of kilometers will such boats be detected when the radar is exposed to the upper projection from an aircraft?

    Most likely, the United States and Israel use similar boats in areas where there are no aircraft as a class - for example, in the coastal zone of the Gaza Strip or Libya.
  4. Div Divich
    Div Divich April 13 2016 16: 33
    Were seen by onlookers ...
    What kind of stealth is it, if they are visible to everyone.