Sounds like a spiffy patrol. Well done.
The thread name implies a question, but there was only one thing to do; jump 'em! That's exactly what you did.
As far as Yamato grazing your boat, you said you were at 30
meters. At 30 meters, the only boats that should be hitting yours are sinking ones you got too close to. If it were 30
feet, I would see Yamato colliding as its draft is around 36 feet or so. At worst, it would have destroyed your periscope shears and both scopes.
Are you running mods? These really alter damage the damage models and may or may not explain the anomaly with the collision.