The French Secret Service sabotaged a Greenpeace ship interfering with a nuclear experiment, and the Mossad probably sabotaged a Gaza flotilla boat. My suggestion: guard your ships and try to catch a saboteur. Then take his picture and advertise it over the internet. After that, hand him over to the police.
Bomb in Lebanon targets bus heading to Syria, no casualties (Reuters)
from the article: Gaza flotilla activists: One of our ships was sabotaged