Long distance (expedition) hunting

Hello to all of you,
I am currently living in Sri Lanka, me and some friends (you could call us purists) have decied to go spear fishing on coral reefs that are about 5km away from the shore, so far you could say there is nothing unsual, what is, is that we intend to do that without any help from a boat. We want to swim the 5km to the reef, carrying our spear gun, fish bag and buoey/life jacket all the way and then swim again the 5km back home (hopefully with our bags full of delicious fish).
My first question is what kind of fins should we use for such a task, I mean by that, what fins are best for long distance surface (on your back) swimming with some equipment to drag? Given the distance to swim (min 10 km + the hunting) our priority is fully surface perfomance regardless of under water hunting performance, so what would you recomend?

My second question has to do with shark danger, the waters where we will be swimming has a reputation of having quite alot of sharks (the dangerous one being mako and to a lesser extent hammerheads) and even some sea snakes. If we were only there for a quick fish I would not be worried but since we are going to be swimming pretty far away from the coast (with bags full of dead fish on the return) and for a long time I do not want to take any chance so I think at least one of us should have a spear gun which is: small enough that it can be turned fast in the direction of danger and powerful enough to kill or at least damage a mako shark enough to dissuade him from pressing an attack. Do you have any ideas on a gun that could fullfill this role?
But of course our goal is not to kill sharks, if we can avoid meeting them in the first place we would be much happier. I have read that you can buy some electric devises that are supposed to frighten sharks away, do they work? and how? do they work on every type of sharks or only some species? Can you recomend any?

Well that s many questions, I hope at least some can be answered as this small expedition is dear to my heart and I would feel much safer if I had the right equipment.

Well first of all, thanks for all the replys.
I have gotten a few similar questions from different posters so I ll try to answer them in bulk.

1)Marwan you ask me if I have have ever tried a 10km swim before and the answer is yes, I have done it in Norway in the north sea WITH a life vest on, finns and even a small rucksacks filled with junk to simulate equipment. It was in the open sea though a strech of islands were conveniantly placed on my way in case I got to tired (which I never did). The swimming lasted 6 hours and though I was a bit tired at the end I still felt like I could swim an extra 5 km without problem maybe even 10 though that is less sure. My main problem was that although I was wearing a wet suit, I started feeling quite cold near the end (it was summer and the water was around 18 celcius) .
Now in Sri lanka the water temp is usually between 24 and 27 celcius, for a normal swim you do not need any wet suit but for such a long time I think I should get one, but I do not know what model would be the most appropriate with long sleeves and leg or without, 3 or 5 mm ?

It has too be stressed what a huge difference having fins and a life vest on makes for such a swim, previously I and a friend had swam on fraction of the strech I did (maybe 1.5 or 2 km) without any equipment, just a zodiac following us, and I must say I was totally exhausted, I could not swim much more. Having a life vest means you can stop in the middle of the ocean and rest without problem and that your head is always out of thet water for breathing (plus the added safety if things go wrong), having fins means you use your powerful and durable leg muscle instead of your weak arms for propulsion. It is amazing how long you can keep going swimming on your back with a slow regular kick in the water, it s almost like walking.

2)On the other hand you ask me if I have ever done some spear fishing and to be honest the answer is no. Normal fishing I have done alot of, scuba diving too, sailing, ocean kayaking and lots more to do with water etc... I have tried and done them all but spear fishing I have yet (and am eager) to try. I am not going to go on that expedition before a month and a half, in the mean time there will be plenty of time to start with some more orthodox spear fishing, but since I have to buy a gun first and since they are not cheap I thought I would ask for advice before purchasing one.
You also ask me about my profile, well I am 23 years old man from Norway and work for an ngo in Sri lanka, I am in good physical condition and I have recently started training by swimming with my pair of standard scuba diving fins an hour or two in the sea daily. My friends (all ngos too) have a similar profile though some might have more reservation about the whole enterprise.

Our Swim will take place on the east coast which is the quiet coast during this half of the year so I am not too worried about currents and that stuff. Nonethless it would be good if we could find some chart for these, I have looked on the internet for a web site with that kind of info but so far have not found anything. For navigation I will be taking my GPS (in water proof container of course) and we will all carry a bottle of water each and maybe some small snacks. My friends will all take standard spear guns for fishing but I want something which I feel confident is capable to deal with a shark since I feel responsible for their safety as I came up with the project in the first place. A power head would be great but I thought that stuff was only used by navy seals and couldn t be purchased by the public. As for the shark shield, I am only concerned that it works on the big sharks as I feel confident that as group of a couple people, the small sharks should leave us alone, anyway the only sharks dangerous to man that are reported are the hammerhead and mako which are not small to begin with.

I am going to look up the fins you talked about, it might be a valuable purchase if they prove more effecient than scuba diving ones. I thought that given the equipment we are carrying scuba diving fins which are designed for a swimmer carrying alot of drag would be more appropriate but I am not that much of an expert in that area and I ll follow any advice that is given to me on the matter.

Lastly some people have said the whole project is reckless. But that is the whole point: the challenge, taking a boat would destroy that aspect and turn the adventure into a run of the mill fishing trip. You are only young once and life is not meant to be zero risk all the time. Anyway I don t think that this expedition is very dangerous given that many people have swam much longer distance without any of the equipment we ll be using.
It s a moderate risk, just enough to give you a little thrill and make the expedition more exiting.

Well well well...

What a barrage of "don't do it" advice.
I think many of you don't realize a 10km swim with life vest and fins isn't all that hard, probably because most of you have never tried it yourself. That being said alot of the warnings/advice that was given is sound, if not always practible:
with the kayaks I have used, you can't jump out and in in mid ocean, try to enter a kayak that isn't docked and it tips over, floods with water, and all you can do is tow it back to shore.

The currents are not that strong on the east coast of sri lanka, I've already paddled with my surf board to within 1 or 2 km off the coast and I never felt a current I couldn't swim against. That being said it is an issue, don't any of you know google earth like equivalent for ocean currents world wide? I just can't find any website with that kind of data for Sri lanka.

A bigger problem is shark protection, as some of you have said it is not very realist for me to provide adequate protection for the rest of the group (especially if it gets dark and visibility starts to fall) so the best option seem to be buying shark shields but I have searched the forum for info about them and it seems they cost a minimum of 700$ and don't last long which means you have to buy additional batterries for them. 700+ $ is alot of money just for one fishing day, I doubt I can convince my colleagues to spend that much money on that. Besides they appear not be work hundred percent though I don't really understand why? Do they only work when the shark aproaches slowly but not if he is charging you at high speed?is it size? it looks like the manufacturers themselves don't know when their device works and when it doesn't but anyways...

Probably the most recurrent theme in the warning against this small adventure is that they are too many variables too which I kind of agree. Maybe I will try to find a closer reef to go to, say 2km away for a start and see how it works out. One poster also mentioned the lack of backup solution and he is right, I think I will try to arrange to have a boat go to the reef and take our fish with it to the shore, that way we won't have to tow that shark bait all the way back. The idea of a warterproof radio is also good, although I don't know if it's easy to find one in sril lanka.

Somebody mentioned some spearfishing in Trinco, which brings another concern to my mind,there is war going on in Sri lanka with quite alot of fighting between the SL navy and the sea Tigers, I wonder how the navy would react if they found a bunch of frog men with spear guns a few mile of the shore, espacially around Trincomalee as there is quite alot action/fireworks going on over there.

Well that's it for now, thanks for all the informative replys.