Buddy System in competitions?

Contrary to your assertion, there are many pairs competitions around the world, including international meets. Basically, spearfishers share one float and cannot dive together (one must always remain on the surface) and do not put a distance between them bigger than 25 m. In some systems, divers use two floats and remain up to 50 m between (two float lines lengths) and dive together. Accidents are indeed non-existant or almost nil.

Believe it or not, top spearfishers themselves are those more against the pairs system. :hmm

Jose, I've seen you post from the first day, but I couldn't make up my mind on what to say in reply: in facts many spearos are dying, and when you face death and tragedy you loose every certainty on what is right, on what you could have done before.
For me the safest system is the individual boat system (used in nationals, Worlds and euro champs) rather than the buddy-in-water system.
Let's examine pro's and con's, strictly safety wise, of course just my personal idea and not the Holy Bible.
PRO's of the individual boat system
-Your assistant standing on the boat, who is generally a spearo and a diver himself, may have a wider point of view on the area; the boat can rush swiftly to you if necessary, restore you on board, bring you fast to the coast or to the medic boat, call emergency with radio or cell phone.
CON's
It generally takes more time for the boat assistant to localize your exact position if you're stuck underwater and to jump in to rescue you. It takes more time for him to help if you surface in samba or syncope.
PRO's of the buddy in water
-the buddy can rescue you faster if he sees you motionless under water, and can immediately be there to prevent you drowining if you surface in samba/syncope.
CON's
-If he sees you motionless underwater it's probably too late for saving your life or integrity (irreversible brain damage occurs after 4 minutes with no oxygen). And if the visibility is poor, he won't see you at all. And then if you have serious injuries, what can a buddy do, there alone with his ass in water, no boat, no telephone or radio, coastline one mile far for example? Morevover: if he's just there to watch you (like it has been experimented in some comps) you can't expect that he'll keep maximum attention for 5 HOURS! (that's how long most comps last). And if he's spearing himself, say 50 meters from you, how can you rely on him in case of emergency?
Resuming
Since 4 years ago, almost every competition in Italy (whose federation counts 800 competitive spearos) was based on the individual boat system.
Then the federation promoted swimming comps (no boat) and pairs comps (even with only one single speargun to use in turns!!!), to facilitate the acces to competitions for the young ones who can't afford a boat (youngmen are students or don't have much money in general). Well, after the last fatality last week, I have news then the federation will stick back all the way to the one-diver-one boat system.
Also technically, the pair comps were not very succesful in the spearos consideration. If each of the two spears for himself, it's just a summatory of points. If one spears and the other watches in turns, it's crap: you may spend one hour to "read" the area, and when you finally have understood how the fish is behaving there, you pass it all to the buddy, who may have a different approach, different characteristics, a different "feeling".
A good example of pairs comps is the Champions' league. But there they have two spearos, each of the two with his own guns, and one boat following each couple. But in this case, the fact of being a pair has almost nothing to do with safety.
Just my bagful of 2 cents coins, sorry for long post but you asked ;-)

Having had a competition just this weekend, I have to say I agree with Spaghetti on the safety system I think a responsible and observant diver on a boat is probably a better alternative than a in water buddy due to a few factors,
1- Spearos normally dive 10 to 25m to get to fish, and can move around down there quite a bit, if you only have 3 to 8m vis, you wont see them anyway.
2- Being a competition there will probably more than one boat in the water plus other water users there for their own reasons, a buddy in the water cant necesarily warn a oncoming boat about a diver down. We all know how some pleasure cruisers behave in the water.
I do however agree that a extra flaot line connected to the weight belt can be advantagous for both in water and boat buddy.
A on boat safety and backup system also has its downfalls but Ill start with the pros,
1- You can react quicker and get a diver to help faster.
2- If your observant and keep and eye on your divers at all times youll imediately know when something is amiss, even if its not, I always go and check if Im the one operating the boat.
3- You can place the boat between the divers down and oncoming trafic, forming a barrier between them and other boats forcing them away from your divers.
4- In case of a probable shark attack, which can easily happen especially here in sa, you can evacuate your divers quicker than with just a buddy there with them.
Now for the cons of a boat,
1- Its not always that easy to just jump off the boat, it might drift away or land on a reef, seein that we mostly hunt on or around those. Thats why I like the idea of an extra line as a safety, you can pull them closer if need be.
2- Divers tend to seperate quite a distance from each other, so you have to run around between the two or three in the water to check on them at all times, if my divers down seperate too far for me to properly check them Ill pick up the stray and take them closer to the group.
3- In some instances when there is more than one boat diving the same reef it gets hard to descern between your own and divers from another boat. Properly marked floats helps in this case.
Well thats my personal point of view, and its what works for me. In the end of the day we're all in there to enjoy the water, and the biggest part of your safety comes from yourself. If you feel uncomfortable or tired dont go down and dont take unnesesary risks.
Safe diving

As far as I know the British Nationals has never seen a pairs competition although individuals scores are added up to form a team score for 3 divers. In all the years the comps have been going I don't believe there has ever been a fatality?? It might be because generally UK spearos don't have to dive as deep as their mediterranean friends but even so, we have very strong tides and currents so who knows what the explanation is.