difference of roles and day to day on assault ships

hello all,
i am to start training for the royal marines next month and am trying to do my homework and where would best suit myself upon completion, i am applying to be a tel's tech (as allready a qualified electrician)
but i realy like the idea of being attached to an assault ship, and so i was wondering, what the differences are between HMS Ocean and HMS Bulwark.
the day to day life, roles in operations?
best opertunaties for further learning and studying.

any help would be most apriciated, or even links to where to find it myself, ive tried the navys site but its very vague.

thanks for your time