Moving to 2.4Ghz - Help!

I currently have 2 boats. An IOM using an AM 75Mhz transmitter and receiver and, an EC-12 using an FM transmitter and receiver.

I just got a Spektrum Dx5e and 2 AR500 recievers. I want to run both boats with the one transmitter.

I know I have to bind each receiver to the transmitter.

But, can I just plug in my servos to the AR500 and go after I bind?
How do I find out where to plug in the servos. The AR500 is not marked Ch1 and Ch2.
What about the EC-12. It need 3 Channels
I have:

My boats are currently wired so the boat battery does not connect to the current receivers. I assume that is no problem for the AR500s as well.

IOM servos
Hitec HS300 - rudder
RMG 280 - sail

EC-12 Servos
Hitec 725BB - main
Hitec 605?? - rudder
Hitec ??? - Twitcher

Anything else I should know about or consider?
I know I have come to the right place to get my answers.

OK Mr Scudman… With the IOM things are simple. That is provided you have the MODE 2 version of the radio. (ratchet throttle on the left stick)
The rudder servo plugs into the Aileron channel (either one, it does not matter)
The winch plugs into the Throttle channel.
The winch which is also plugged into the battery will power the receiver. (You may have to reprogram the RMG to get the correct number of turns which is another drama again)

As for the EC12, that is also the same, but, for the twitcher you have a choice as to which control you use.
The left/right proportional action on the left stick is the Rudder connection on the receiver.
Or the full on/full off of the gear switch may be a better bet for the twitcher. You choose.

Please let us know how you get on. Best of luck.

Thanks Ian,
That is a very clear explanation and I do have Mode 2

The only thing I do not get is the Full on/off of the Gear Switch.
I have 3 switches on the top of the radio.
On the left side is a momentary switch that I believe is the Trainer
And another on/off switch not identified

On the right side is a Rate switch with Hi/Lo

Is the Gear switch the un-marked on of the left?

YES! it is.

Thanks Ian…I have completed installation and both boats work just fine. I had a bit of trouble binding, but that was the result of not following the directions fully. Pull the bind plug out before you disconnect power. Found that you can adjust the end point nicely with the fine tune button on the sail stick. Now I need to rig them both and make any adjustments with sheets. Thinking of gluing a plastic straw inside the boats to keep the antenna straight and using a bit of velcro on the receiver to it up high away from the bilge.

Was wondering if there is a problem with obtaining a signal if the receiver is located say on the starboard side and the boat is heeled over on a port tack sailing away from you at 50 or 75 yards?

No my friend, there should be no trouble with lack of signal no matter at what angle you sail.
Keeping the receiver up high out of any water in the bilge is always a good idea as is the old straw trick.
Sounds like you have it sussed, no excuses now, time to go sailing, that is unless you live where the water gets solid at this time.
All the best.