I met an owner of a steel boat badly damaged by a whale encounter, so I have always started the engine which works, but I've still had a few too close for comfort situations like a large (10m) Minke trying to bow ride my just over 12m yacht, he thought he was a dolphin! And a mother and calf sperm whale near T bone at dusk, that was a little scary as it was a few weeks after seeing the damaged steel boat.