You guys are so spoiled 
I am stuck with 20kg check-in almost everytime. I travel with around 45kg check-in stuffs pretty much everywhere (not including the 2 carry-on that my poor back has to carry, about 15kg).
Depending on the mood of the check in clerk, sometimes they gave me a nasty look and did not say anything. If I can help it, I would group check with a few other fellow divers and they are usually ok about that. Sometimes when my karma is down, it is time to whip out the credit card. Sometimes the extra fee was high enough that I just upgrade to business class and they would ignore my excess baggage limit.
This past Lembeh trip I just sent half of my stuffs out with the liveaboard when they departed Thailand. All my stuffs are on the boat now since I am going back there in 5 weeks and probably will just ask them to bring everything back on the boat since the boat is coming back a month after my September trip.
Sometimes I wish I never heard of wetpixel and never learned the existence of dSLR 