A few years ago it would have been " i was flying my C172/182/206/210 (insert appropriate lighty) at 500 ft coastal and had a near hit with a gyrocopter.
The height limit for model aeroplanes - be they quad/hex/octo copters, electric fixed wing, turbine powered model jets etc is 400ft as far as I am aware, and given that they don't typically have accurate altimetry (many have telemetry that shows some parameters but altitude is usually just GPS altitude not barometric) and it is damn near impossible to accurately pick how high the model is flying at, the difference between 4 and 500 ft is pretty small.