I believe in the principle that everyone should start with just food and water, and any basic supplies necessary for survival such as road flares and a hunting knife. You're washed up on the shore of an unknown land - how is it likely that you just happened to have a sidearm on you when you get up onto your feet? It's more likely that you'd have a hunting knife on you than a pistol if you were any other normal person. I can guarantee that this method will make it that much more tense. Folks will work together in order to scavenge for supplies up until the moment someone discovers a weapon - and then, from there, all hell would break loose. They could either gun down the people they've traveled with or continue on until a better, more opportune moment arises like when the other folks in the party would have a better weapon you could pick off of them. Starting with a weapon - even a weak one - just seems unlikely in the case of this kind of scenario.