Re: What binoculars do you use?
I use the cheap £15 7x30s available from all sorts of different shops. always got 2 or 3 pairs on board. doesnt matter if they are dropped / fall in / get wet / are lost - they are disposible. the optics are quite good enough in my experience, and they have the great benefit that being light they do not shake / wobble anything like as much.
the "proper" bins stay in a locker if they are on board (I must have a look for them)
P>S> Aldi had some good ones on special offer recently. 12x32 about £15 and excellent for casual bird watching.
this post is a personal opinion, and you should not base your actions on it.