Why and How to Keep a Ship's LogWhen it comes to boat trips, one of the most useful habits that any captain can have is to keep a detailed log. Logs were once used not only as a captain’s private journal, but as a detailed account of every aspect of the boat, crew, and journey. Before the world was fully mapped and the ability to position oneself longitudinally was possible, logs often provided the only clues on the course that was necessary to a specific location. Whether you are a prolific journalist or simply an organized person, the benefits of keeping a good log continues to be beneficial even in the days of GPS and satellite positioning. Logs should be kept in a place where it is easy to grab while underway and either write or read, and should have its own designated writing instrument assigned to it to make writing quick and easy to do. A waterproof case is helpful, and can be as simple as a plastic bag. Here are a few different things to consider keeping in your log:

What to Keep in a Ship’s Log

The Boat Journey Information

Why and How to Keep a Ship's LogThis is the traditional use of a log. A record of journeys can be detailed or simple, long or short. The typical items that are included are time, date, weather, destination, and passengers. A note of whether fuel was taken on, any changes that needed to happen (like a course alteration due to weather), and engine hours are great items to have as well, as they can be useful later. Those who love wildlife can also keep track of seabirds or marine mammal sightings. There is really no limit to the things that you can include: fishing locations and luck, the wonderful dinners cooked on board, or even the funniest joke told during the trip. The more colorful a log that you keep, the more likely it is that you will want to go back, read it later, and reminisce about your times at sea. If you are the captain and your spouse is the writer, you may want to assign him or her the duty of keeping the log.

Boat Maintenance

Maintenance is an important thing to have in your log. A record on the specific services done, the dates, and any special techniques or considerations that were needed will be helpful in keeping your boat engine in good working order. Any notes on whether you noticed something beginning to wear out, the condition of things that were replaced during a tune-up or winterization, or special tools needed to get into a certain tight engine compartment are all good things to keep track of. Creating a regular maintenance schedule in a log for all parts that need work is also a good way to structure a section. By keeping it separate from the more narrative portion of a log, this makes it simple to find all the information needed about what services are upcoming on your vessel.

Boat Equipment Information

This is similar to keeping a maintenance log, but it deals instead with items that need replacement occasionally. Keeping a list of important vessel items that expire on the inside cover of your log allows you to write, in pencil, all of the expiration dates of these things. This can include first aid kit items, flares, disposable fire extinguishers, the zincs protecting the metal surfaces on your vessel, lines, and even your boat registration. Boaters can also keep a cleaning schedule for things like wood elements on the boat, paint, and sail cleaning and maintenance. By keeping it in a prominent location, it allows you to remind yourself each time that you open the log that there needs to be an upcoming change. Keeping the dates in pencil lets you change out only the expiration date without requiring you to find a new, less prominent writing space.

Why and How to Keep a Ship's LogHow Logbooks are Useful for Future Trips

Though logs are great as storybooks, the more detailed your stories are, the more likely that they can be used to make your boating life easier in the future. This is not just true of your own log, but the logs of others as well. For example, in Puget Sound, the log of George Vancouver, for whom both the city and the island are named, has given a wealth of information, and continues to be used today. It gave a detailed account on shellfish poisoning and helped to teach doctors that this was native to North America and suggested that it was most likely due to clam consumption. It also lists his meetings with locals and the interpretation of place names. The log, along with the logs of other explorers at the time, continue to be used today by tribal archaeologists to prove the extent to which they traveled, and extend a certain tribes rights, like fishing, to these grounds based on their traditional use. Here are some great ways to use a log to extrapolate info about your boat:

Tracking Your Boat’s Fuel Consumption

By keeping track of engine hours and miles or nautical miles traveled under power, two things can be learned. First, you can understand the distance that you can travel under power between fuel stops. If you are planning a trip someplace with remote fuel in between, such as the inside passage in Alaska, this is a great way to know if your boat carries enough fuel to get from stop to stop without the need to bring extra. Of course, current conditions in locations like this will require you to have a certain amount of safety reserve, but the principle is the same nonetheless. A manufacturer’s approximation is not as accurate as your own log’s documentation of nautical miles/engine hours versus fuel gallons burned. Second, this is a great way to trace back the beginning timeline of a problem, or recognize it before it becomes too serious, or too expensive. A regular tracking of miles or hours versus fuel can help you to determine when an engine, drag, or other problem is beginning to affect the efficiency of the boat under power.

Using a Ship’s Log as an Itinerary

The use of your own log or someone else’s is a great way to recreate a journey. This can be a historic journey, such as a trip along the Mississippi following all of Huckleberry Finn’s stops, or a voyage along Lewis and Clark’s path along the Columbia River. It can also be a repeat of a favorite sailing voyage through the Florida Keys, or an excursion to track down all of your grandfather’s favorite fishing holes. The more details in the log that will help to identify the spots that created great memories, the more meaningful the repeat journey can become.

Treasure Hunting Using a Ship’s Log

The use of logs has long been a treasure hunter’s tool. There is still a large amount of sunken treasure in the South Atlantic and Caribbean seas, as a result of failed pirating attempts and surprise storms. Divers who choose less populous reefs may get lucky with an underwater metal detector and find something of historical and monetary value. Tracing the regular travel of a certain sailor, ship, or captain is one fun way to do this. The same principle applies if you are trying to track down where along your journey you may have lost your brand new swim ladder, of course.

How to Switch Out Logbooks

Of course, the more avid a writer or boater you are, the more logs you will accumulate. Boats are traditionally tight quarters, and the idea of a shelf (or several) full of logs is usually undesired. Most captains only hold on to one log at a time on board the vessel. Logs can be used one per year, or be switched out once they are full, depending on your preference. When it is time to change out a log, starting a new one is best done by taking what was learned about maintenance and equipment from the last. Transcribe the equipment page, or use this opportunity to replace these items and write in new expiration dates. Take a record of last maintenance on all major parts, and the engine part replacement numbers used in those fixes. Document the last known mileage of the boat, and whether it was a decline from the previous log switch. Taking the time to transfer this information will save you information digging time when you really do not have it, like when you are underway with only one log.

Why and How to Keep a Ship's LogWhatever use you find most pertinent for your own ship’s log, keeping a log is a rewarding, practical and valuable practice. It is a great way to get family members who are less comfortable with captaining involved, like a spouse or teen, and a wonderful way to recall the most magical parts of your trip. In the winter months, when your boat is safely tucked away in storage, a log is also a great way to remember the best trips of the previous boating season, and to serve as a jumping off point for planning your new season of trips.