Programming motorola - busy channels on UHF

Hi there,

I am seeking advice on the possibilities of programming a fleet of Motorola GP328 UHF with CPS R06.12.05.
Is it possible to tweak them in anyway to keep interference from nearby users to a minimum?
They are used on board a ship for communication between bridge and deck/machinery spaces. In crowded places like for example Singapore the interruptions from nearby ships are almost unbearable, so we are looking for any solutions to this and your help would be greatly appreciated!

Best regards

Change the PL tones. Use oddball tones and it will help to minimize interference. Example, I use DPL 532 with my radios and have very little issues.

This is crazy - changing tones solves nothing. Remember that tones simply prevent your radio hearing conversations that are somebody else. They do NOTHING to cure interference from users on the same channel. If your squelch opens with the right tone, if somebody else comes up with a different one, they wreck each other until the tone is hidden enough to reactivate the mute. Co-channel interference is never cured by tone squelch. All it does is keep their conversations from annoying you. If you both press the PTT at the same time, you both get interference. only a different frequency will cure this problem.