I bring one phone; my wife brings hers…that’s 2 phones.
Funny things happen to electronics in moist and damp conditions.
I don’t like being dependent on anyone for anything. Have seen way too many times what happens to those who are “traveling light”, depending on others gear in a pinch.
No need to suffer needlessy; no need to be a victim of your own lack of preparedness.
BOB
P.S. “Beware the helplessness of the chronic victim”.
If I waited to paddle with someone I’d never be out 95% of the time.
To much gear is never a problem to little can be a serious problem.
My immediate thought to this thread was “women”, so yours covers that.
ppine’s three boats with 2 dogs is a better idea, but don’ tknow how he gets them to paddle. Dogpaddle?
I generally stay out on the west coast of Scotland for weeks/months. I always carry 2l water, firewood, spare paddles, pump and a bailer. Two knives, one a divers knife and the other a full tang blade. Backup hexi cooker to complement my twig cooker. We have three hundred days of rain per year here so it is necessary to carry enough wood to cook with for around three days.
I wouldn’t say I travel light and I’ve never depended on others in a pinch. If I’m leaving busy areas I tend to have two means of cooking, two ways to start fire and even if I’m not planning on camping I generally have at least a poncho which can be made into a shelter. I do almost exclusively travel alone and almost always without any means of contacting anyone. Actually satellite phones would be the only means of communication most times anyway.
I can’t even count the amount of straps we have in the car, they don’t take up much space. But curiously, I carry a complete set of the those hullavator pins. I can’t imagine loosing them, but you never know, and I’d hate to have to either leave the boats behind or strap them down to the bare crossbars. (We take the “moose antlers” off at the launch and store them in the car.)
I’m still working on making more paddles, but will carry a storm paddle once I make one.
We met a a couple this last weekend, the both carry a tow rope kit. I can’t see the utility of that, you only need one, right? But… what if you are in a large group, either of you might need to tow someone.
key fob.
That has happened to us on group paddles where we needed 2 or 3 towlines several times. Twice, it was tag team towing where two or three towers make a chain of boats for long distance tows of seasick/food poisoning paddlers, and one time where a member of the group got a large stray fish hook through her hand, and we got her to shore for an ambulance. Her husband went with her, and we took turns towing both of their boats 3+ miles back to the launch. Redundancy of safety gear is never too many.
Remind me not to go on a trip with you Wayne_Smith. 
Sea Sickness, Food Poisoning, Hooks through the hand, sounds like quite lot of bad luck in one spot. Bet your group is glad you are prepared.
Lighters, always carry 2
Arms and legs
head lamps
fire starter
Always carry a second set of glasses. For day trips I leave them in the car.
A hat, maybe.
Yeah on the spare paddle and two methods of bailing. In my canoe I ususally use a milk or bleach jug, with the bottom cut off, and a large sponge.
Two paddles.
Two methods of making fire.
Two knives.
Two pair of glasses.
Anything I can’t survive without. I might not bring two of everything, but I have a plan to improvise important items if they are lost or broken.
I both love and hate these threads! Now I have more things to be stressed out that I don’t have 
That said, I have:
2 whistles
2 knives (one on PFD, one multi tool in hatch)
4 compasses (deck compass, map compass, digital on vhf, digital on watch)
2 watches (waterproof, one with compass)
3 electronic flares (2 are strobes, 1 is infrared, 2 on PFD, 1 in hatch)
2 containers of water (1 on PFD, 1 in hatch)
3 methods to patch boat (duck tape, marine epoxy, denso strips)
multiple zip ties
multiple lengths of Paracord
4 carabineers (2 on PFD, 2 I’m hatch)
2 plastic compression hooks for Paracord
multiple batteries (backups for vhf radio, charging cell phone)
-edit-
2 paddles
2 tow ropes (1 on PFD)
I’m sure there is more too but I know I sound like a crazy person so I’ll stop there. But to my initial point, no ways to start a fire!, no backup vhf, aaargh! Also you have personally had to carry one end of my boat so you know how heavy all that crap is 
If it can be found, look at Verlen Kruger’s equipment list. If he didn’t have it, you don’t need it.