In the UK, 2.4GHz can be used for both surface and aircraft use. Because of its convenience and teething problems having been eradicated, many (probably the vast majority) of marine modellers are buying 2.4GHz sets when looking for new gear. Particularly because the inexpensive ‘Planet’ type sets’ available though most retail outlets are cheaper than an equivalent 27 of 40MHz set.
However, 2.4GHz doesn’t work in submarines.
Spektrum have two new sets due out later this year, a Dx8i and a Dx10.
Hitec now have an Aurora 8 channel set.
The Multiplex Cockpit SX 2.4GHz is very good as well.
What both Hitec and Multiplex both have is the facility to change from Mode 1 to Mode 2 without actually adding springs/ratchets inside the transmitter. In other words by turning a screw on the back of the case, a vertical axis stick can be changed from self-centering to non self-centering (with or without a ratchet). This is currently unique to Hitec and Multiplex (who are the same manufacturer) but is useful for model boaters whose electric boats usually go both forwards and reverse.
Paul Freshney