Jump to content

How would you mark up charts for navigation?

Dan Foster

Recommended Posts

Imagine that you had an infinite, free supply of NOAA charts, and could therefore mark them up to your heart's content to make a customized chart before each paddle. Imagine you could draw lines and get bearings and distances added automatically. You could move compass roses around, or add a magnetic grid overlay. You could rotate the chart so that magnetic north was up, or your destination was at the top.

What would you do or add to create the ideal chart for use out on the water?

The reason I ask is that I write mapping software, and I've been realizing as I paddled this summer that sea kayak navigation on the water is a lot different than stopping in the woods to check my compass against a topo map. Having a chart oriented to magnetic north helped, and having pre-determined magnetic bearing lines for critical crossings REALLY helped. I tried a few things out, and have some ideas how I'd like to prepare my maps for next season. But I'd really like to start a discussion about what's worked for others in the past, and what issues you're still facing out on the water (or in camp planning the next day).

If anyone has real, marked-up charts from expeditions or trips they've done in the past, I'd love to see them.

Link to comment
Share on other sites

Here's a link to a series of posts I put up that are based on two workshops I gave last winter. This includes how I mark up charts.


Mainly, I keep the chart orientation as is, but I have lines that point along the magnetic lines spaced apart by one nautical mile, so I can readily get distance information as well as bearings.

I've marked up real charts by hand, but I've also downloaded charts and used Adobe illustrator to mark up and annotate charts (e.g. current directions, timing, speeds).

Link to comment
Share on other sites

John, I've been following along with your posts here on NSPN, and recently stumbled across a tracking podcast where you discuss more primitive ways of navigation. Great stuff!

I agree that having the magnetic lines spaced one nautical mile apart really helps, and having the perpendicular east-west lines makes it easier to construct a "mental compass rose" at the closest grid intersection, rather than having to guess the angle from your current position to a target, and mentally bring that angle over to the chart's compass rose.

Link to comment
Share on other sites

Hi Dan-

If you're blue-skying ideas, I'd start with a TOPO map, and find a way to add near shore features and depths. Land features are often more useful to me in piloting and navigating than deepwater channels and the like. Orienting chart top to magnetic north is a nice feature. Flexibility in chart scale might be nice. For example, a complicated piece of coastline plotted out with grid features at 0.5NM (~1km) at 1:10K or 1:20K and also a larger scale of 1:50k for the entire area. And the last think i've got for now is a printing organization such that a larger chart/map is readily broken down to useful overlapping sub-maps with user defined two sided printing.



Link to comment
Share on other sites

Thanks for all the suggestions, Phil. I've found that in a lot of cases, USGS topos have more relevant information and better scales for paddling, and they tile together better in places where you're paddling off one chart onto another. On a few occasions this summer, I'd paddle with a topo or aerial photo with my intended route, and the NOAA chart on the reverse for reference. I spent some time playing around with NOAA's vector ENC charts, which let you turn on and off various features (deep water soundings, for example). It's still pretty crude. I had better luck taking a recent topo or aerial photo, and overlaying buoy and light data on that.

Link to comment
Share on other sites

Very often the chart is folded on my deck so I cant see the long.s and lat.s on the perimeter of the chart, and the scale and compass rose are often not viewable when chart is folded (which it always is, someway or another, depending on where I am and where I'm going ) So I like magnetic north lines parallel every nautical mile, across the whole chart; makes course plotting or orienteering with handheld compass easier. These lines then double as a scale.

I also like to place long.s and lat.s here and there on the chart so I can figure them out no matter how the chart is folded on my deck.

Link to comment
Share on other sites

I hope this one is attached - it's a simple marked up map of Isle au Haut. Not a big deal, but I did it with Illustrator.

I did the same thing with charts of squam many years ago, they were double sided so one side looked like the one you posted but on the other side I added compass bearings for the crossings, put ins, etc... They were 11"x17" and laminated, I made many of them and gave them out so (hopefully) everyone on the trip learned some navagation and they all got a chart to keep for their return trips.

Link to comment
Share on other sites

Bathyrythmic data not so important as Phil suggested except around coastlines.

Kayakers are sometimes "at sea" guesstimating which direction water might flow at different times of the tide cycle (see discussion from Sebascodegan trip report[Gurnet Strait]). Might be nice to have this and other " warnings to strangers" information in a "callout" form. Other places that come to mind are mouth of Kennebec and Hell gates (slack ebb occurs 1 hour past posted LT @ station X; max flood approaches Y knots).

Important aids to navigation that I would like to see highlighted or magnified include buoys, day markers, and topo features such as towers, chimneys, etc.

Would be good to have magnetic lines spaced X nm apart, as appropriate to map scale, while keeping True north parallel to edge of map, as mariners refer to both references from time to time.

Lat/long grid lines every 5 minutes, but add labels to lines every ?6 inches, to account for the folding of the chart, as Peter mentioned.

Would be nice to have labels on sandy or pebbly beaches-I have been fooled before (Big Be-atch)!

Symbols and callout data for kayak-friendly launch sites.


Link to comment
Share on other sites

Nothing much to add since many good suggestions made. If you have not attended one of the BCU nav classes, that might be good since you will work with ordnance maps and UK charts which have many useful features not found on the USGS and NOAA maps and charts we typically use. Since you asked for a chart that had been used, I've added an image of a chart I used for a 5 day, 80NM trip I worked in this summer. What you see are the only marks I added to the chart and that was for a crossing. It looks primitive, but I spent some time the night before going over things so there is more do it than meets the eye so to speak. While I spent a fair bit of time just ruminating with charts and plotting software at home while dreaming of journeys, I tend to rely mostly on an unannotated chart, compass and fingers once on the trip. For this particular trip I ended up launching 15 miles from where I planned to and while I visited the places I wanted to, the route was also quite different than planned. So not having lots of stuff on the chart based on what I thought I would do as opposed to how the trip unfolded was good. Just my minimalist approach to wandering about, but that does not mean all the navigation stuff isn't used.

Ed Lawson


Edited by EEL
Link to comment
Share on other sites

Here's a few pix of some of my marked-up charts. This one is from a "print your own" kiosk (no longer there) at BBLeans. I've added magnetic N, cans (green, odd) and nuns (red, even), not exact, but estimated from corresponding nautical charts.


Another, from Delorme, with added MN, scale, and campsite waypoints.


Topo with transferred buoys, and island symbols indicating day-use/private/public/and MITA.


Delorme with buoys, MN, and 4 predetermined waypoints for reference.


Booklet chart indicating island waypoint, MN lines, and MCHT/MITA islands (red=camping, blue=day-use)


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...