I have a 10 month old boy, who, although great at home, with children and normally off his lead in the park, is a horror at his dog training class. He bursts through the door fur flying and ready to have a go at anything he sees, although he does settle down after a while and manages his down stays etc. He was the same at his puppy socialisation class too.
Howevever, last week, off his lead in the park, he had a go at another dog - a much bigger, but younger and more submissive dog. No harm done but....
He's my first skye - is this normal adolescent behaviour? will he grow out of it? or should i get him castrated?

Why not ask the breeder?  They should be able to tell you the character of the breed and what to expect from their particular breeding.  I have heard of and met some sky terriers who were very dog aggressive, but then I've also met sky terriers who were ok with other dogs.  The breeder should be able to guide you in this.

Perhaps all the practising at his dog training class is now paying off. :(  Was the puppy socialisation class free for all play?