Diving into water is a hazardous recreational activity if done (a) from other than a diving board or diving platform, or (b) at any place or from any structure where diving is prohibited if warning of the prohibition is given. Government entities are immune from liability for injury suffered from engaging in such activities under Gov. Code 831.7. This decision holds that the two portions of the statute marked (a) and (b) above are independent alternatives. So diving into the water from a breakwater is a hazardous recreational activity even if no warning is given. The city is therefore immune from suit for the spinal injury plaintiff suffered in a drunken plunge off a breakwater that rendered him a quadriplegic.