Welcome to the world of RC Submarines!

This is a really brief introduction to the world of RC Submarines. I'll add to this list as I find out more. Tim Smalley has an excellent site designed to introduce the hobby to new people. The SubCommittee is also a great resource for information.

Let's start with an exerpt from one of the RC Submarine community's oldest and most knowledgeable members, Mr. David Meriman III. His writing style can be a bit, shall we say.. direct, however the information is invaluable and his points very concise. Read and comprehend!:


"For further study of this and related ballast water management systems I can not recommend enough Norbert Bruggen’s, MODEL SUBMARINE TECHNOLOGY (ISBN 1 900371 049). It is a must read for anyone wishing to build and operate submarine type r/c vehicles. Within the pages of this excellent book there is an entire chapter dedicated to the subject, an excellent over-view of the many means of getting water in and out of the ballast tank. And don't read his book casually. STUDY IT! And, while you're at it, brush up on your math and circuit reading skills, those disciplines a prerequisite to understanding his presentation.

(Wait!  ... is that too much to ask of you? Are you put off by the challenge of  becoming conversant in those two technical languages? Well then, let me be blunt: If you can't comprehend the varied and vital topics in Norbert's book -- and circuit schematics and basic math conventions are a big part of it -- may I suggest that you're not qualified to pursue the game of r/c submarining in any meaningful way. This is not a game for lazy, stupid, inattentive, no-talent, puffy arm-chair Admiral's. Consider the reading and comprehension of Norbert's book your entrance exam. Understand it and your in. And if it's over your pointy little head, then get out before you dump a bunch of cash on stuff  you're not equipped to understand or use).

R/c submarining is the game of the elites in the field of r/c vehicle fabrication and operation. It's not an entry-level activity!

Other suggested reading includes my Cabal Reports, found here: http://vabiz.com/d&e/articles.html

There are several forums out there in Net-land dealing with r/c model submarines. But, most of those suffer from a terribly high noise to signal ratio and do more harm than good for those wishing to get the straight skinny about r/c model submarining. Exceptions to that bleak observation include the German Sonar, British Model Boaters Mayhem, AMS, and a few other bastions of wisdom, informative pictures, and captivating video. You got a computer … go find 'em!

Component -- Any stand-alone non-electronic item that is part of a sub-system.
Devices – Any stand-alone electronic circuit (receiver, ADF, MPC, X-tail mixer, Lipo-guard, BEC, ESC, etc.), pump-motor combination, servo, solenoid or other function specific item aboard the SD
Dynamic type diving -- A model submarine that does not change its weight to make the transition from surface to submerged operation. A submarine that relies on the dynamic force generated by the hull and/or control surfaces as a consequence of motion through the water. That force needed to push the submarine down against the ever-present force of buoyancy.
Discharge Line -- The flexible hoses, manifolds, and nipples that routes pressurized air from the LPB discharge nipple to the ballast tank.
Displacement -- the amount of water (expressed either as weight or volume) pushed aside by the immersed model submarine. A surfaced submarine -- with a sizable fraction of its structure out of the water -- displaces less than the same submarine totally submerged. An object in a fluid 'floats' when the weight of the thing is countered by the buoyant force exerted by weight of the fluid it displaces. See: Archimedes principle. A submerged submarine, in order for its displacement to match its weight, has to take on a specific amount of weight to transition from surfaced to submerged trim if it is to become neutrally buoyant submerged. That's the job of the ballast sub-system -- to take on that extra weight needed to counter the buoyancy gained when the topside portions of the submarine become immersed as the boat submerges.
Freeboard -- Distance from surface trim waterline to top of the submarines deck. Boats of high reserve buoyancy stand very tall in the water. Boats of low reserve buoyancy, sit low in the water. Look at the freeboards of the Soviet ...err .... I mean Russian AKULA and American LOS ANGELES class to make the point. The Russian boat has about 35% reserve buoyancy. The American boat, only 15% or so. A model depicting a boat of high freeboard needs much more ballast tank volume than a model representing a submarine of low freeboard. RCABS is suitable only for r/c model submarines representing  boats of low freeboard.
Hover -- The practice of making fine adjustments of the submarines weight to effect changes in depth; vertical travel through precise management of either main ballast tank water or water handled by an auxiliary ballast sub-system.
Induction Line -- The flexible hoses, manifolds, nipples, snorkel head-valve, and safety float-valve components that route either outside air or SD air to the LPB pump intake nipple.
Kit-Assembler – Anyone who does not scratch-build. Most of you are mouth-breathing, short-bus-riding kit assemblers! I am a kit-builder (I MAKE kits) I'm also a kit-assembler -- I transit between both worlds. On rare occasions, like this screed, I will engage in intercourse with you mere mortals ... intellectually, of course.
LPB – Low Pressure Blower. A pump (or, if you will, a compressor) with the ability to move air from point A to point B. As used in my SD system, its one of two sizes of positive displacement, diaphragm type pumps that can move both gas and liquid. The LPB is the heart of the basic LPB ballast sub-system, and with modification is the heart of the SAS ballast sub-system.
Manifold -- An internally ported resin block with external brass tube nipples used to interconnect LPB or SAS flexible hoses.
Modular Concept -- Or, Dive Module. The terms, used extensively in Europe, describes the earliest examples of the removable water tight cylinder system. A single, removable cylinder within the model submarine that contains the sub-systems needed to animate the r/c vehicle. Nick Burge of the UK is the first to popularize the concept and is responsible for its adoption and wide spread use throughout the world. Commercial versions have since been produced and marketed under such names as: Craycraft system, Eden system, WTC, SubDriver, Modular Command System, Experimenters Cylinder Kit, etc.
MPC – Motor Pump Controller. Very low profile electronic switches produced by Kevin McLeod. Designed to mount directly to the after face of the LPB motor. The controller draws line current directly from the battery through the system mission switch. A three-wire lead and plug runs from the MPC to the ADF’s fail-safe output port, sharing it with the ballast sub-system servo through a Y-lead.
Planing Up -- Driving the submarine up to broach the sail above water through the dynamic force of the hydroplanes and hull. The preferred way a submarine gets its main induction or snorkel valve above the water so that ballast tank de-watering can be accomplished with only the LPB.
RCABS – ReCirculating Air Ballast System. The inflation/deflation of an air bag within the wet space of either the WTC or the annular space between the WTC and submarine hull, physically changing the displacement of the submarine. An air pump pushes WTC air into the collapsed bag, the bag inflates, displacing water, getting the boat to surface trim. Releasing a stop-valve between the bag inlet and the WTC’s interior permits the high differential pressure between WTC interior and bag (a partial vacuum created within the WTC as the bag filled with air) to deflate the bag, water comes in to a volume equal to the lost volume of the bag, essentially increasing the weight of the submarine, and the boat sinks. This ballast water management sub-system was popularized by Dr. Art Broader and is still championed by many American r/c submariners.
Recovery Depth – The maximum depth at which the SAS can de-water at least 1/3 of the ballast tank volume. Below that depth back-pressure on the sub-system creates a differential the LPB can not fight against.
SAS – Semi-Aspirated ballast Sub-system (OK, the acronym is a corruption of the term… sue me! I'll be damned if I'm going to cal it the, SABSS!). A ballast water management sub-system that either employs outside air or internal air (within the SubDriver's dry spaces) to discharge ballast water.
Static diving – A model submarine with the means of changing its displacement by changing its weight. The additional weight of the full ballast tank accounts for the buoyant force presented by the above waterline portions of the submarine once immersed in the water. A condition where the total weight of the submarine equals the weight of the water it displaces when all portions of the structure are immersed. Once full submerged, the submarines weight and buoyant forces cancel out and little dynamic force from the control surfaces or hull is required to achieve changes in depth. Unlike a dynamically diving model submarine, the statically diving submarine can remain at rest fully submerged.
SubDriver – Also known by the acronym I invented over twenty years ago, Water Tight Cylinder, or WTC. A removable system that constitutes the watertight containment that houses the propulsion, control, and ballast sub-systems that animate a model r/c submarine. Though I did not invent the concept of the removable cylinder (it appears that the honor belongs to Nick Burge) I am the man responsible for its introduction into the marketplace here in the States.
Sub-System – Dedicated devices,components, and structure that together perform a specific task, either autonomously or by command.
System – A collection of sub-systems so integrated as to work together as a whole. The basic r/c submarine SubDriver is a system comprising three sub-systems: propulsion, control, and ballast.


Greg Sharpe's RC Verne Nautilus

What is an RC Submarine?

An RC sub is basically a surface ship that has the added ability to dive under the water and return to the surface again. These models may have static (ballast system) or dynamic (no ballast system) diving capabilities, although many sub-humans will say that dynamically diving subs are really just waterproof surface craft and not true submarines.

What's the point? You can't see them anyway.

Well, no. Not when they're under four feet of water. It's the challenge of diving a submarine and then bringing her back up safely that's the ultimate reward. There's also a sense of satisfaction watching the surface craft skippers on shore jump in surprise when your sub pops up just behind them, ready for a torpedo shot! When ballasted negatively (not recommended, but real fun), you can actually "park" your sub on the bottom and wait for unsuspecting prey to pass by.

What's the best place to get a sub for a beginner?

This is probably the number one question that I get! Its an exciting hobby, but it can be a daunting thing to get into. There is lots to learn, and "getting your feet wet" properly is important in order to eliminate the possibility of getting frustrated, losing a valuable submarine, or hurting yourself! There are a few different kits that I'd recommend:

  1. Dumas Akula: A cheap, dynamic diver that allows you to get the idea of driving a sub. Not a static diver (you need to go fast in order to pull the model under with the oversized dive planes
  2. SubTech Marlin or Albacore: Beginner subs that are about halfway between the costs of the Dumas Akula and a more mainstream RC sub. Look to put about $700 or so at the end of the day (no labor charges included)

How do they work?

Very basically, the static diving submarines will take on water to the point that they will easily dive under the water with a little bit of help from the control surfaces (dive planes). When surfacing, water is forced out of the ballast tank either by a pump or by compressed gas of some kind. Dynamic divers use their control surfaces only to force them under the water. When speed drops, their bouyancy forces them to the surface. See a video of the internal workings of an RC sub WTC from my video here (Part 1) and here (Part 2).

How does the signal go underwater?

Radio signals will penetrate water. Freshwater is the best for getting clear transmission to your model and there are many experienced sub drivers who have operated (properly constructed) submarine models in depths in excess of thirty feet. Once you start getting additions such as chlorine or salt in the water, you will see serious reduction to the maximum depth you will be able to control you model. When operating at the surface, the only limit is your radio system. Submarines can be operated in heavily chlorinated pools, or even in the ocean, but you depth will be limited to a few inches, at best. Operating any deeper will require an antenna addition, as you'll need to keep the antenna above the surface of the water in order to maintain control of your model.

How much do they cost?

Lots. Don't let anyone tell you otherwise. You can get pool toys that will let you piddle around in your backyard pool for a few hundred dollars, but a complete RTR RC Sub in a decent scale will set you back a good $1500 to start with. Sub hulls go for around $400 to $500US, and a complete WTC (water tight compartment) with full electronics suite will add another $1000. Tack on a decent radio, and your pretty close to $2000US. You can do better or worse for price depending on what you're looking for, but that's a pretty good idea of what they're worth.

How fast to they go?

I guess that depends on the model and the drive system, but a good average is a fast walking pace at full throttle. Modern nuclear subs are more hydrodynamic than older submarine designs such as WWII fleetboats, and are therefore typically faster.

How deep do they go?

All they way to the bottom (all the RC sub sites say that, so I guess I might as well, too). My WTC should be good in excess of thirty feet or so, but I really do not want to go that deep. In practical terms, you should only go as deep as you can see, typically less than five feet, and that's plenty enough water to get into trouble with. Radio signals penetrate a lot of fresh water, but things like chlorine and salt water significantly reduce your radio range.

What are they made of?

Blood, sweat, and tears mostly. Hulls are generally made of fibreglass or GRP (glass reinforced plastic). High end hulls are manufactured with epoxy. Some smaller hulls are made from vacuum forrmed plastic. WTC (water tight compartments) are typically made from clear lexan so that the owner can easily check for leaks. Acrylic tubing works, but you need to be aware that it is very prone to cracking at the edges.

How do I get one?

There are two options: build it or buy it. Building is cheaper (though not by much), but is infinitely more time-consuming and you're end product will generally not be as high quality as the suppliers can put out. My Nautilus project has kept me busy for many years, and after a while it gets a bit frustrating. If I could do it all again, I'd buy my first kit, and then worry about building the next project while I can enjoy the first in the interim. But that's just my opinion. Some of the suppliers are listed on my Links page , but a full listing can be found on the Subcommittee website .

What about missiles and torpedoes?

You betcha! Both have been done before by many talented modellers. Dave Merriman of D&E Miniatures has actually built a six tube torpedo launcher for his 1:72 scale Alfa submarine! Most of these weapons systems are powered by compressed gas. Stay away from the Estes rocket engine idea. Apparently fire and water don't mix that well.

What kind of radio do I need?

Submarines with a ballast system require a minimum of four channels (throttle, dive planes, rudder, ballast). Make sure that your radio is operating on 75Mhz (surface frequency). Airplane frequencies technically work, but if you mess up someone's model airplane while running your sub, get ready for some unhappiness from the owner and from the government if they catch you. In terms of channels, if you're thinking of adding addtional features such as torpedoes, missiles, periscopes, etc..., then make sure you have some extra channels. I bought an Airtronics VG600 6-channel for my Nautilus (four standard channels plus working lights and a spare channel).

What kind of extra features can you add?

Anything that you can dream of, build or buy. Missiles, torpedoes, lighting, periscopes, working hatches, sound effects, diesel smoke (for WWII diesel-electrics, of course), bow thrusters, and much more. Just make sure that you have enough channels on your radio and space in your hull for all the goodies. Save room for working video and sound, and a new fish-finder on the market actually lets you add sonar to your model with the display sent back to you on shore!

What happens if it doesn't come back up again?

You cry. You curse. You pray. Then, you get wet. Your sub is probably mired in the mud or hung up on some weeds. Take a set of swim trunks and a mask to the pond with you in case something like this happens. When she doesn't come up, sight some landmarks or throw a marker where you last saw it. Then head out to sea and hope for the best. Be sure that you have a failsafe system installed that will automatically blow ballast if you lose radio signal. Another option is to build a buoy that gets released after a set amount of time. One exceptional idea is to use a tic tac candy to secure a float to the hull. After a period of time, the tic tac dissolves, and releases the buoy. It needs to be replaced at every run, but it makes sure that you get your model home every night.