I run my air boat with a 40 find less interference with 40 than 27

as far i as know you can use 40 and 27 for cars boats etc but planes have to use 35 but you cant use 35 for boats maybe just a ploy to get you to buy more than one transmitter lol

i keep my 35 for my plane the 40 and 27 for my boats not want my 35 one getting wet way too expensive i get mine from e bay usally £6 to £7 for a transmitter and you can pick up a receiver for £5 if you use gixen its a free sniper