What is "skip distance" in radio propagation and why is it not relevant to VHF marine radio?

A. Skip distance is the gap between the ground wave and ionospheric reflection in MF/HF radio — VHF does not reflect off the ionosphere and so has no skip distance; VHF is purely line-of-sight with a predictable range based on antenna height

B. VHF does experience skip propagation — that is why VHF range is sometimes much greater than expected

C. Skip distance only applies to satellite communications

D. Skip distance is the maximum range of a VHF signal — approximately 25 nautical miles

A. To send a digitally coded distress alert containing the vessel's MMSI and position automatically to all DSC-equipped stations and the Coastguard

B. To broadcast weather forecasts to other vessels

C. To make telephone calls from the vessel to shore

D. To operate the radar system remotely

A. A GPS waypoint identifier used in coastal navigation

B. Maritime Mobile Service Identity — a unique 9-digit number identifying the vessel; without it a DSC distress alert cannot identify the vessel to rescuers

C. A VHF channel number allocated by Ofcom for distress use only

D. A vessel survey certificate number required by the MCA