All they have to worry about are winds, and DEADLY ATTACK SWANS!!!
http://torontosun.com/News/TorontoAndGTA/2006/05/08/1569510-sun.html
"As Justin Hayes of the construction firm, Aecon, navigated a small motor boat toward the breakwall for inspection, the male swan cut him off at ramming speed before flapping its wings in a menacing manner."
Menacing, deadly attack swans.
"Not just for Stratford anymore." tm