Yeah you start to notice your ship burning in the 30's levels.

Razzor has a good point. I'd still go heavier on restorer's rather than engineers
though. Call it personal preference. From personal experience restorers seem to
start having a noticeable (though not exactly game-altering) effect around low 30s.
From everything I've read you can expect to see no difference from engineers until
mid 40s to early 50s.
just my 2 bits

Your repairers/restorers basically do squat for you until your in your 40's as well.

Thordic I would say that you have too few supports at the level you are now. You have 5
support slots in a RN CA. One for the scout, 4 for the main supports, plus an extra 2 in
the T slots if you don't AA. With the BB/BC you get another slot etc etc. As you need to
get the sailors to around mid 30's before they start getting full xp from being in a CA,
you need to start levelling in advance of getting the CA.

I have 2 rep, 3 rest, 1 eng at the moment for my CA.

I have read on this forum the Airwind gets very good speed in his POW by using multiple
engineers.

The choice is yours.

Wouln't bother with the second engineer. From everything I've read 1 is plenty for
Brits. You're far better off taking advantage of the nation advantage - namely
restorers and repairers. Your engineer will do squat for you before you're in the 40s.

I suggest you to train two of each engineer, repair and restore

repair and restore will be better