"No Force Death" means that in battle no sailors(recruits), skilled sailors(experts) or officers(vets) can be killed. These crew deaths occur occaisionally during regular battle rooms but have a much higher rate of occurrence in World at War rooms. Thus this event will encourage play in World at War rooms that have a 200% exp rate for these four days. That means that July 6 will be the 250% event plus the 200% in WaW (if you have prem you can add 150% more and add another 30% if you pick up the 30% item in the NF Store) Could make for a killer day of grinding. Oh yeah add double exp for your first win of the day!  :)

i like its..... no death sailor n no RIP............ miahahahaha

Well, event details state when and what "buffs" there will be. 

As stated in here  you can see those things during event:
July 3rd : No force death
July 4th : No force death
July 5th : 250% Vet conversion rate
July 6th: 250% EXP gain rate 

Ergo, only sunday, july 6th, has increased exp gain, there's no mention about 4 days of increased exp so it seems someone here has made wrong assumptions while reading event notes ;)

Regards 

That's what I was trying to say... I guess I put it too politely in my reply to ahab :D

Have any of you noticed that the event has been updated since yesterday?

@captain_ahab:

WaW doesn't give 200% exp compared to GB.

There is no shared exp, and the exp you gain can be 0 or 10x as much as in GB. So your "200%" is way off the mark.