And like their land lubbing brethren, pedalos must give way to everyone 
Red to red, go ahead... Green to green should never be seen. And if in doubt, always turn right 
Hovercraft technically should be given-way to by everyone, although in practice they move so quick that by the time you have made your intentions clear he has already passed you.

One of my favourite things I like teaching soldiers when sailing is sticking the boat in the middle of the solent, clear of the restriction zone, hove-to on a starboard tack and then stopping everything while we sit and have lunch. They are amazed that you can just do that and everyone goes around you.
For something with no right of way the RRS use the phrase "right of way" a lot 
Right of way does not exist in ColRegs, you will fail any exam you take if you make mention to it. I have seen it done

I was referring to the "vessels on a port tack shall keep clear of those on a starboard tack" though, rule 10 
I got muddled in my rules. It is rule 8 I meant:
Action to Avoid Collision
(a) Any action to avoid collision shall be taken in accordance with the Rules of this Part and shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observance of good seamanship.
(b) Any alteration of course and/or speed to avoid collision shall, if the circumstances of the case admit be large enough to be readily apparent to another vessel observing visually or by radar; a succession of small alterations of course and/or speed shall be avoided.
(c) If there is sufficient sea room, alteration of course alone may be the most effective action to avoid a close-quarters situation provided that it is made in good time, is substantial and does not result in another close-quarters situation.
(d) Action taken to avoid collision with another vessel shall be such as to result in passing at a safe distance. The effectiveness of the action shall be carefully checked until the other vessel is finally past and clear.
(e) If necessary to avoid collision or allow more time to asses the situation, a vessel may slacken her speed or take all way off by stopping or reversing her means of propulsion.
(f)
(i) A vessel which, by any of these rules, is required not to impede the passage or safe passage of another vessel shall when required by the circumstances of the case, take early action to allow sufficient sea room for the safe passage of the other vessel.
(ii) A vessel required not to impede the passage or safe passage of another vessel is not relieved of this obligation if approaching the other vessel so as to involve risk of collision and shall, when taking action, have full regard to the action which may be required by the rules of this part.
(iii) A vessel the passage of which is not to be impeded remains fully obliged to comply with the rules of this part when the two vessels are approaching one another so as to involve risk of collision. 
If the Highway code was written a bit like this then it should get rid of this right of way nonsense
