Boat Building Materials & Essential Marine Hardware
Oarlock and Socket
Paddles don't work very well on puddle ducks, you really need to use oars. Here are some simple plans for DIY oars you can make. If you break something on your duck while sailing - no problem, just furl the sail and row home. If you row at an easy pace, you can literally row all day long. One ducker I know rowed 20 miles in a single day, and he is just a regular guy, not an athelete.
Oars are easy to make, but the oarlocks and sockets are a very important component that you want to be reliable, so you should consider purchasing the oarlocks instead of trying to improvise something. There are many different types, personally I prefer the side mount sockets with clamp on locks (the pin part, which clamps onto the oar). But every duck is different, and you need to figure which types work best for your duck.
Inspection Deck Plate
To access the inside of your air tanks, you can use various re-purposed plastic storage containers. I did that for a long time but those type plastics are usually not UV resistant, so I gave in and started buying deck plates (picture to the right) for my boats.
To attach deck plates to boats, I use adhesive bathtub caulk.
It seems to stay rubbery, has good enough adhesive properties to make it stick, but can still be removed by pulling it off.
Sometimes I'll put a couple of aluminum pop rivets with backup plates through a couple of holes just as backup.
Search for words like "inspection deck plate" or "inspection port".