The Harbor screen is not to be trusted

When engineers are close to reaching a higher OH speed,the use of a seaman can give them enough of a boost to reach that speed in game. However the HArbor screen will not show that OH speed increase. AS is withnessed by Lionel2.

The same is also true unfortunately for SD, the extra boost effect a seaman gives the SD provided by other sailors isn't shown in the harbor screen.All it does show is some weird rouding up/down effects.

I did a little in game testing and here's what I found:
IF an AP shell does enough damage, its damage is capped per shell for that ship ( except when it's a critical hit).
In my test I hurled some BB5 AP at a H39.
AP will never do more than 4140 damage per shell to a H39.
So when I see the in game damage numbers pop up above the H39, I can work out the actual SD the H39 has in game.
Then I setup the H39 with crews that the harbor screen said had the same SD, but 1 contained the Seaman and 1 didn't.
The seamanless crew had popups for 1276 damage done per shell, which corresponds to the H39 having 692 SD, exactly what the harbor screen said it should be.
The crew with the seaman had popups for 1185 damage, which corresponds to an ingame SD of 714, 22 more than the Harbor screen said ( a 3+% boost).

So yes a Seaman does boost restore given by other sailors,but the Harbor screen won't tell you by how much.

I firmly believe that the numbers in the right hand column are directly added to the sailors stats.

You're shooting test is very interesting. My next question is: does the seamen only work in support slots or in any slot?

"firmly believe that the numbers in the right hand column are directly added to the sailors stats"

If you read some of the NF documentation, it states that the numbers in the right hand column of a
seaman are different then other sailors and are percentage numbers. It implies that these are "boost" percentages.
Of course, programmers could change this at anytime without documenting.

Seaman performance seems to be so variable that it seems there is some sort of factoring applied
to these numbers, i.e, a 10 ability is not a 10% boost but something smaller, perhaps on the order of
1/10 of 1% boost.

A 10% boost would be along the line of adding 10 vets and this would be enough that it would noticeable
by many players. This doesn't seem to be the case as there are many players who claim their seaman
do NOTHING.

Perhaps the boost numbers or ability numbers are more equivalent to adding experts. After all, a seaman is
supposed to be better then a regular sailor....Not on officer, but a Non Commissioned Officer, say a Petty Officer.
In this case, the 10 ability might be similar to adding 1 expert. This would be a small boost and hard to detect.

This might explain why seaman tend to be more effective on smaller ships where overall crew ability is less and where
additional experts would make a greater impact. This would explain how the overheat speed comes and goes based
on engineer lvl. 1 expert might be enough to boost an engineer to higher speeds when about to lvl. After lvling, 1 expert would not be enough.

The "adding experts" is only a theory but it does tend to explain some of the seamans performances.

it't not a elite fp and aaw,
a us sailor will got +2 aaw and +2 fp
that means your aaw and fp base is +11 only if you don't bve
can if you buy a elite fp to become a seaman,if no bve, your aaw will only be 11,
if bve,your seaman aaw will become 13 and fp become 18