@bismarkhin: You are missing the point everyone is trying to make. What you say is not
true.

boosted late like you said is correct. (10+8+4+4)*1.2 = 31

boosted at lvl 1 would also be the same. 10*1.2 + 8*1.2 + 4*1.2 + 4*1.2 = 31

The boost is applied to everything.

facepalm time.
It doesn't matter if it's level 1 or 54 -> the result is the same. If you do it at level 120
for example, the ability is calculated as if it was done at level 1. The downside there
is you missed out on 119 levels of playing with a boosted sailor. The sooner you do
it, the sooner you get to take advantage of its extra abilities but the final product is
always the same.

I have another idea

Let say I have 2 US Lv 1 eng with growth 11 and ability of 100

If I boost at lv1....when the sailor at Lv54
the growth would be 10*1.2 +8+4+4 = 28
the ability would be 1144
and the ability at Lv80 would be 1844

However, if I boost at lv54....then....when the sailor at Lv54
the growth would be (10+8+4+4)*1..2 = 31....
the ability would be 1226
and the ability at Lv80 would be 2001


So.....my eng sailors are boosted at 1st eng....:P
just my stupid option...

ummm....yea....If there is a cap....then I think boost ASAP would be a good idea

Well, if you're boosting a sailor that will skill cap later on, it's best to do it early so you
can take full advantage of it.

any lvl at any time

what does it mean to boost anyway?

what does it mean to boost anyway?

"General rule of thumb with boosting boost asap and if it isnt boosted after about lvl
76 it isnt worth boosting unless its a fp or engy because fp have no cap so theres
nothing to reach it just makes ur fp that little bit better and engys will hit their speed
cap possibly depending on ship but they can always make their oh time longer "

This is not accurate. Boosting works anytime, any lvl. You get same boost at lvl 1
and you do at lvl 120.

ok. thanks

I recommend boosting ASAP. Not because it makes a difference later on, but because if
you're going to spend the money on a boost you may as will get maximum benefit by making
the grind easier.