Model warship combat

While many models use a combination of switches and/or relays physically actuated by servos to control the propulsion system, most newer models now use either Electronic Speed Control units or solid-state switching boards, such as those found in Robot combat, greatly reducing the complexity of the wiring of the propulsion system. Propulsion is provided by electric motors coupled to shafts passing through stuffing tubes driving semi-scale propellers. All active mechanical systems are required to be operated via electrical or pneumatic means. Any and all mechanisms relying upon chemical combustion which could contaminate the water with fuels, oils, or other chemicals are banned.[6]

The cannons use steel balls ranging from .177" to .25" in diameter as projectiles, typically propelled by CO₂ or compressed air. As of 2009, a small number of smaller "Big Gun" ships are equipped with cannons powered by compression springs. In Big Gun combat, club rules usually include provisions for the arming of torpedoes, usually represented by a fixed cannon firing 0.25" diameter projectiles.[7] Although individuals have attempted to construct self-propelled 0.25" diameter torpedoes, their use has yet to be formally documented or demonstrated. Additionally, vendors have demonstrated working prototypes of weapons control systems suitable for Big Gun combat that would enable multiple turrets on a single vessel to be coordinated as a single weapons battery, allowing multiple weapons to simultaneously target a single vessel. All Pyrotechnics are specifically banned from use to protect the safety of people and animals, in addition to preventing environmental damage.[6]

• Arizona Cannon/Single Barrel Gun System - easy to manufacture cannon named after one of the first model ships in which it was successfully implemented [8][9]
• Ball-bearing interrupter - one or two steel balls in-line with the gas supply line interrupts the feed of ammunition into the breech, ensuring that only one projectile is fired at a time
• JC White Rotating Cannon - first widely successful multi-barrel rotating turret [10]
• JC White Torpedo cannon - similar to the rotating cannon without the rotating magazine on top [11]
• Indiana Cannon - a refinement of the JC White Rotating Cannon [10] so named due to the US State in which it was first manufactured. Evolution of the JC White design into the Indiana Cannon marked the point at which the design encountered widespread adoption in the Big Gun format.
• Jam elbow - [12]
• Negative pressure/Quick Exhaust Valve - Typically uses a Clippard Exhaust Valve in its construction and relies upon a discharge of pressure from a pneumatic control circuit to actuate the cannon.[13]
• O-ring breech -
• Piston interrupter - a "piston" in-line with the gas supply line interrupts the feed of ammunition into the breech, ensuring that only one projectile is fired at a time[14][15]
• Sliding breech -
• Spring-loaded breech - [16]
• Spring-fired/Spring-powered cannon - instead of directly utilizing exclusively compressed gas to impart kinetic energy to the projectile, a spring affixed to a piston to compress gas in a chamber or a spring directly acting on the projectile is used.
• Spurt cannon - a spurt cannon is a type of fast gun cannon that lacks a mechanism to interrupt feeding of steel balls into the breech. Subsequently, it will continuously fire until either the supply of ammunition or compressed gas is depleted.

• Depressing - due to concerns for safety and the goal of inflicting damage to an opposing ship at or below the waterline, cannon can be configured to incorporate negative elevation with an adjustable mechanism
• Fixed - Fixed cannon cannot be trained, requiring the captain to maneuver the ship to bring them to bear on a target instead.
• Rotating - To enable a ship to bring the maximum possible firepower to bear on a given target, cannon can be equipped with a mechanism to facilitate rotation if the corresponding cannon on the real ship were so equipped. Additionally, cannon rotation permit a ship to continue to fire upon a target while maneuvering, potentially increasing the number of successful hits within a given period of time. While uncommon in Fast Gun due to a combination of complexity and limited tactical benefit, cannon rotation is common in the Big Gun format.[17]

• Straight-magazine — Steel ball ammunition is housed in a relatively straight length of rigid or flexible tubing and can be gravity or force-fed into the cannon breech.
• Coil-magazine - Ammunition is housed in tubing as with the straight-magazine configuration; however, the magazine tubing is tightly coiled, sometimes around the cannon riser and/or valve so as to reduce the longitudinal volume required for the cannon. Ammunition can be gravity or force-fed into the cannon breech.
• Canister-magazine - In a canister-magazine configuration, ammunition is housed within a cylindrical chamber integrated into the cannon body. Ammunition is typically gravity-fed into the cannon breech.

While some early vessels were built in 1/150 scale, scales have become standardized with the most common construction scale of 1:144, although 1:96, 1:72 and 1:48 scale modeling groups also do exist. The majority of hulls are constructed from either fiberglass (with penetration windows cut into it), or scratch built with wood ribs. The exteriors of the ship's hulls are sheeted balsa wood, which allows the relatively low velocity cannon projectiles to penetrate them. The penetration is intended to let in water, with the model sinking if the onboard bilge pumps cannot compensate for the rate at which water enters the hull.[6] Superstructures are often constructed with a combination of lightweight wood, plastic sheets, thermoset plastic resins, and corrosion-resistant metals. Smaller vessels such as light cruisers and destroyers often incorporate a less-durable but lighter superstructure in order to maximize the displacement available for weapons systems. After combat, the models typically escape real damage other than that to the balsa skin, and can typically be patched and turned around in 15–30 minutes.

Instead of a single battle, multiple battles or sorties are combined to form a campaign of combat events, sometimes with a preceding battle dictating the available of rearming opportunities afforded to a team in the following battle. A campaign can also consist of multiple objective-oriented battles, or team free-for-all battles.

Typically held in sessions divided by vessel combat units or combat value, during a free-for-all each captain operates his or her vessel to sink or damage as many of the other vessels on the water as possible while minimizing the damage incurred. It is often played in a "last-man-standing" format where the winning vessel is identified simply as the last to sink or be disabled.

Objective format combat is typically executed in the form of a scenario, requiring each team to accomplish specific objectives to earn points and/or win the scenario. Such combat may involve sides of asymmetrical strength, such as when attempting to simulate a recreation of a historic battle.

One of the most common combat format across the different model warship clubs, team free-for-all involves the division of players present into two teams that are equal based upon a combat strength rubric (i.e. units in Fast Gun or a combination of displacement tonnage and cannon count in Big Gun), which then sortie against each other in accordance with the club's rules and scoring system.

NTXBG's Richelieu and Missouri duke it out on the water

Kagero (1/72 scale) stern damage

Unlike Fast Gun clubs, Big Gun clubs operate based upon a loose confederation, with each club reserving the ability to establish and maintain its own rules, provided that they coincide with the spirit of Big Gun Model Warship Combat. With versions in 1/48, 1/72, 1/96, and 1/144 scale, Big Gun Model Warship combat clubs have provisions for cannon caliber and armor thickness to be scaling according to what existed on the prototype vessel. Big Gun Model Warships allow weapons to be installed in rotating turrets as if they were mounted on the historical vessel.[6][18][19] Damage Control is accomplished via a centrifugal bilge pump capable pumping a regulated volume of water out of the hull. The volume allowed is based on the prototype vessel's displacement. Typically, the flow rate varies from 30 gallons per hour (GPH) for the smallest ships to 90GPH for the largest ships.[6][18][19]

Big Gun clubs are largely descended from the now defunct "North American Warship Combat Association" (NASWCA) dating back to late 1981/early 1982.[3][4]

Principally known as Fast Gun by its members due to few restrictions on rate of fire, this format is sometimes also identified as Small Gun because of its exclusive use of .177" (BB) caliber guns. About 80% of active clubs are of the fast gun variety, in which all ships are built in 1/144 scale and use .177" caliber guns, which in most cases are installed in fixed mounts but may rotate depending upon ship class. Additionally, all ships are fitted with a standardized 1/32" thick balsa wood 'Armor' to yield an easily penetrable hull. Damage control is accomplished through the use of centrifugal bilge pumps fitted with either a 1/8" or 1/16" diameter flow restrictor. Clubs that follow this format include the International Radio-Controlled Warship Combat Club (IRCWCC) and Model Warship Combat, Incorporated (MWCI).

A subset or adaptation of small gun is known as Treaty Combat. Treaty Combat, abbreviated simply as Treaty, incorporates uniform caliber weapons, armor, and combat units in a way similar to that defined in IRCWCC or MWCI rules; however, speeds and pump capacities are limited based upon the prototype vessel and displacement, respectively. Thus, Treaty Combat incorporates some of the reduced-cost aspects of the Fast Gun format with some of the scaled characteristics of Big Gun.