Welcome to the forum, there is no visitor swing or marina style moorings in Hayle that I know of (could be wrong).
There is a fisherman’s pen owned by the harbour company where they keep nets pots etc and you may be able to keep the RIB there for the week however it is not that secure and a mate of mine had all his stainless steel work nicked from his boat last year.
Harbour Master office
The Hayle Harbour Company Ltd.
The Old Customs House
Tel 01736 754 043
Fax 01736 756 632
The other option is to put the RIB on a caravan/tent pitch for the week, try asking the following who have sites near the slip in Hayle:
Let me know how you get on.