Last thing I want is some D*#K disturbing my tranquility whilst I lay on the beach. Take you gay overalls and get a painting job. At least you will be doing something productive.
Now don't tell me you need to be at 500' to spot sharks. Tuna spotters work from 1000 to 2500' Prawn spotters vary from 1500 to 4000', Samon spotters target 1500'. You pick sharks out quite easily from 5000'
Waste of time, If people new just how many times sharks were in there swimming area, no one would enter the water.
Give them some polarized sunnies, put them in a hot air ballon and tie them to the beach. Low cost 24hr protection.