I have just received a ICOM fix-mounted VHF radio. To my surprise, its
instruction says that I must keep the bottom of the radio antenna at
least 1-meter (3.3 feet) away from our heads if the antenna is mounted
in a small boat. I have never heard this before. Is this for real?
Does this have something to do with strong radio frequency may boil our
brain or cause cancer? Does this restriction also apply to 3dB
antenna? Does this mean that I need to use an extension to keep the
radio antenna further away from our heads?

Thanks in advance for any info about this "unexpected" restriction.

Jay Chan