These are some of the more common questions that we get asked about radio control in model submarines.

QUESTION: What sort of radio should I use?

ANSWER: We have a problem in that the frequencies previously used - 27 and 40Mhz are no longer supported by manufacturers. The newer radio control systems on 2.4GHZ DO NOT work underwater whatsoever!! no matter what people tell you

So we are now reliant on second hand equipment. One promising solution is the use of openLRS technology (Developed for Drones.) It's use for submarines was discovered and pioneered by Tim Senecal in the US. It works on the UK legal frequency of 458-459MHz. (433MHz in the US.) The AMS had discussions with the UK frequency regulation body(UKRCC) in March 2015 and its use was recognised: It is still experimental, to an extent, but shows promise with some exciting new features such as Telemetry.


QUESTION: Does the RX antenna have to be out of the water?

ANSWER: No, it is not necessary to extend the antenna outside the watertight compartment. But if you do wish to extend the antenna outside, remember to seal the end of the antenna wire with an epoxy resin to prevent any contact with the water.


QUESTION: How deep can you go down with a model submarine?

ANSWER: Most people find that just over 3M (9-ft) is about the maximum depth that control is easily maintained (swimming pools) but this is with the transmitter in close proximity to the model. In practical terms we have found that at a depth of around M is best for open sailing. If the operator cannot easily see the model it is in effect uncontrollable. However at any distance and even at periscope depth the model may still be invisible to the operator, so be cautious about the distance and depth that you sail at.


QUESTION: How does the radio work under water?

ANSWER: In fresh water, reception with the antenna submerged is not a problem. When the model is at a distance the radio signals tend to bounce off the water so reception below a few feet degrades as the model moves further away. Salt water does interfere with the signal so it is best to avoid the sea, coastal or even in some cases tidal waters completely. The most enjoyable submarine operations are in clear water and close to the bank where the model may be easily seen and manoeuvred. Water is not the same quality in any two locations and sometimes it can be even vary at the same location. Remember the conditions of the water may have a great effect on the way your submarine operates. Colder water is more buoyant than warm water. (Icebergs only float in the cold regions of the poles!) Thus a submarine diving in cold water could be in trouble if it hits a sudden warm layer. The saltier the water, the more buoyant it is. Therefore if you set the ballast of your model in salty water, you could have trouble when submerging in fresh water.


QUESTION: How about chlorinated water as found in swimming pools?

ANSWER: The same applies, but to a lesser extent, with chlorinated water as long as the chlorine levels are low the signal will get through. The temperature of the pool will affect the buoyancy of the model though so always be prepared to adjust the trim with each sailing.