For now at least, we are coastal cruisers, so our ditch bag is packed with that in mind. I have a small waterproof bag stowed near my quarterberth where it can be easily grabbed while heading up the companionway steps. It has an older but still working handheld radio, two handheld but ultra bright CREE flashlights, extra batteries, a boy scout survival kit (whistle, signal mirror, compass), a small roll of duct tape, a small waterproof first aid kit, two bottles of water, and a laminated card with the toll free customer service number for AmEx should we be without wallets but need access to money in an emergency. I like the idea of including space blankets and think I'll add a pair to our bag.
We have an inflatable dinghy we either tow or stow on the foredeck, so I think it likely we would be in that should the worst occur. For that reason and because we like going on dinghy adventures while at anchor, I also have a waterproof plastic canister containing an emergency dinghy patch kit, a whistle, and a small first aid kit lashed to the underside of our dinghy's seat with shock cord.
