I like to keep a paddle log, where I write up comments about each trip I make. This is also where I write up my gear lists. When I feel like spending a day paddling, I can scan through the paddle log to see if I feel like revisiting a place I've been before. It's also enjoyable just re-reading the log and remembering the trips that I've taken. Here are some ideas of what to write in a paddle log.

• Trip number - I give each trip a number, so I know how many trips I've taken. So far, it's up to 48.
• Mileage, time - After every trip, I review the route on the map and measure the mileage. I use a mileage computer that consists of a small wheel (actually a small gear) that controls a pointer on a dial. The dial is about 1 1/2 inches in diameter and displays "inches". As you roll the small wheel along the route on the map, the gears turn and the pointer moves, counting how many inches you've rolled along. When you've rolled along the entire route, out and back, you read the dial, then multiply by the map scale. This gives you how many inches your actual trip was. This is not a very useful number, so you convert the inches into miles. For example, on the ADC county maps, the scale is 1:24000. This means that 1 inch on the map corresponds to 24,000 inches in the real world. If I measure my route on the map and the dial says 19.5 inches, this corresponds to (19.5 x 24,000) = 468,000 inches of actual paddling on the water. To convert this unwieldly number to miles, divide by 63,360 which is how many inches in a mile: (468,000 / 63,360) = 7.4 miles. I also log when I arrived and departed and how many hours/minutes I was paddling. Using the mileage and time, I can compute my average speed for the entire trip.
• Cumulative mileage, cumulative time - Just for fun, I keep track of the cumulative miles and hours that I have paddled. So far, the numbers are 420.2 miles and 185.6 hours.
• Driving information - I note how many miles and how long it took from my house to the put-in. I also note any special driving directions and comments about the driving trip.
• Put-in information - There are a lot of things you can write down about the put-in: what is the condition of the ramp or put-in area, is there a steep dropoff, how much parking is available and what condition is the lot, does it look like a safe place to leave the car, is there a clean grassy area to assemble the kayak, is there drinking water available, is there a bathroom or outhouse (if not, is there a private place to take a leak), is it busy or quiet, is there a fee for admission or using the launch area, what are the hours of operation throughout the year, is it closed in winter.
• Water conditions - How much tidal current and tidal range, will you have to walk across mudflats at low tide, what is the time offset from some standard tide reporting station, is there a wide open area of water so the wind can build up waves, what kind of boat traffic and how much, are boat wakes a problem, is it fresh or salt water, what is the water quality (clean, muddy, scummy green, etc.).
• Bottom conditions - Is it muddy or sandy, are there submerged tree stumps or other obstacles, are there tricky shoals to avoid.
• Weather conditions - Wind speed and direction, temperature, cloud cover.
• Trip notes - What wildlife did you see, what was the shoreside scenery like, were there any places you could beach the boat and get out to stretch, did you have any troubles with the boat, gear, or traveling, were there any important navigation notes for the route taken.