Secure boat storage.

We are hoping to take our 4m tinny on holidays to Hervey Bay to do some fishing etc. Unfortunately the place we are staying, near the marina, does not allow boats on trailer on site. We have enquired at the marina however we cannot afford their rates (pensioners). Does anyone know somewhere close by where would could safely and securely store the boat so we can have easy access to it. We are happy to pay a small cost but just cant afford the $240+ at the marina. Last time we left it on the street and EVERYTHING was stolen out of it. Any help would be deeply appreciated.