Nobozo; while a plane can be as low to the water as the pilot dares, the rules say the plane must be 500 feet from persons or property. This guy was buzzing lines of snowmobilers at less than 100 feet AGL. Note: the FAR mentions "OPEN" water, so above the ice, the minimums may be 500. Does anyone know how that is interpreted?
FAR § 91.119 Minimum safe altitudes: General.
Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:
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(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.
Upthesaukee; I've attached a cropping of the tail from the original shot - no way those are numbers. Doesn't look like any under the stabilizer either.