You know the new guy that becomes an instant 'Internet' expert? The kind that shows up for a mountainous 5 day speed hike with a canvas tent and full sized aluminum folding cot? Yeah, that guy. He usually means well but forgets that others far smarter and wiser came before him. Well ... I do not want to be that guy or even close to him (I guess him/her is the phrase now days). So in a desire to not show up screwed up as a football bat at a tennis match I would respectfully ask for your input on the following.

I am developing a Ditch kit. The theory is to wear it with a PFD while afloat (I am an excellent swimmer, former WSI and SCUBA instructor. I always wear my PFD.)  I am favoring a small backpack/day pack design to make it easier to carry when not on the water. I do not like fanny packs, even a little. The concept of a small pack for a 'just in case' event is, IMO (my opinion being that I should ask those who know more than me) a 'must do'.

So here is the list I have so far. I claim NO credit for this list. It is a result of combining lists from many sources, many of which are from this forum. Please let me know your opinion.

DITCH KIT
IF IT IS NOT ‘ON’ YOU IT WILL NOT BE ‘WITH’ YOU.

Small backpack design for wearing over PFD. Attached by carabiner to PFD. ALWAYS wear PFD.
Ditch Kit is your CONSTANT companion. When portaging or walking away from beyond direct, unobstructed, line of sight, ALWAYS take Ditch Kit (minus PFD).

CONTENTS: all in waterproof bags and/or ZipLoc bags
3 flares (in pocket of PFD)
2 smokes (in pocket of PFD)
1 signal mirror
1 lighter (2+ better)
Vaseline cotton balls (pencil sharpener for making thin, dry tinder from twigs)
1 magnesium/steel fire starter
1 space blanket and/or SIL tarp (tarp on top of bag contents, under bug suit for quick access)
Whistle (in addition to whistle on PFD)
Knife (in addition to knife on PFD) (Swiss Army?)
550 cord
SPOT
Backup Compass: Primary compass is ALWAYS on person.
small flashlight.
duct tape.
Water filter (water purification straw)
Hydration bag and/or Nalgene bottles
Picaridin Insect Repellent and/or DEET   
Tick removal
Duct tape
Mesh bug suit with hat (pack on top of Ditch Kit for quick access)
Advil and/or Ibuprofen
First Aid kit and/or Blowout kit
Hand line for fishing with hooks, lures and leaders
Protein Bars/ snacks
Wire saw

Rope loop attached to the canoe carry bar prior to launch for water re-entry.
Split foam pipe insulation over the gunnels for a silent paddle rest