Hydrographic Surveys

There's no question that the internet has made sailing, cruising, and boating in general more safe. We have access to a plethora of weather and navigation information, all at easy access unless you happen to be offshore, accessible even then if you have enough money. The sheer volume of safety information is sometimes its demise, though, simply because there's just so much of it that it's hard to keep track of where you want to go for it and how much of it you want to use. One of the most valuable bits of information that a lot of cruisers neglect is the hydrographic survey. If you're traveling anywhere on the East Coast, using the inlets and then the ICW, the surveys are invaluable.

The hydrographic surveys are listed by district. The Wilmington District carries most of the surveys  for the Atlantic ICW, coastal inlets and crossings, harbors, side channels, and river projects. The Jacksonville District carries the Florida ICW and inlet surveys. Before transiting any of the areas it's a good idea to check the applicable survey. If you think you're going to be away from internet service, you can save the pdf files for viewing offline.

Here's a example of the hydrographic survey done for the Lockwoods Folly Inlet, done April 13, 2018. Most of the really notorious inlets are surveyed pretty frequently so the data is usually pretty accurate. It's pretty easy to see where you can go, and that you absolutely can't follow the magenta line in this case. The aids to navigation are moved frequently here and you can see that right now they go almost all the way to shore before they turn back to the channel. A few years ago, while transiting this inlet, we watched as a 40-foot sailboat run so hard aground here that he fell over on his side. He was single handing and was clearly following the magenta line on his autopilot. 

Hydrographic surveys can also be of use when determining the heights to bridges. Here's the survey for the Wilkerson Bridge in the Alligator-Pungo Canal. If you do use the survey for this purpose, just be careful to check the dates of the survey. This survey is from 2016 so it wouldn't be any use at all as a current estimation of water depth and bridge height.



Maybe the most beneficial use of the surveys is for determining what inlets to use when coming in from offshore. There are a lot of inlets along the coast that are extremely useful, but where the bottom changes so frequently that they require local knowledge. Surveys offer a wealth of that knowledge. Here is the Masonboro Inlet at Wrightsville Beach that we use frequently.




It's important to note that not all of the surveys look the same. Here's one from the Jacksonville District for the Saint Augustine Inlet on the Florida east coast. Note that the depths are printed right on the chart and are not color coded with a legend the way that the Wilmington District does it. It's also listed as eight pages in one file. Use the scroll bar on the side of the panel to see all the pages in this example.



It's also important to really pay attention to the details in the printed sidebar. On this example of the Naples to Gordon Pass survey, it says that it's a post Irma examination. Pretty useful for knowing how the storm changed things.




Unfortunately, the formats are not standardized. Each district has its own formatting and not all are as user-friendly. The New England District formatting is probably the most difficult to navigate. After going to the main linked page, you click on the navigation projects drop-down menu and then proceed to each individual state. Then they either offer a zipped pdf file for download, or you can click on each individual harbor or river for that survey.


Hydrographic Survey Districts:

There is a new site where all surveys will eventually be listed together, the main survey listing by state and inlet. It's fairly slow to load and respond to input, so be patient. You choose a state, then an inlet and then if there is a recent survey for that inlet it will be listed so you can click on it. If there is no recent survey it will tell you that. It's a good first effort at standardizing the surveys, but they have a long way to go.

Here are some of the more common districts.

The New England District

Wilmington District

Jacksonville District

Mobile District

Galveston District

San Francisco District

Seattle District (takes you to the main survey page)


There's a ton of information out there available to us as mariners. Navigating that information can be as difficult as navigating the waterways themselves.  I've found the surveys very helpful and if you use them and you have any additional pointers, please leave them in the comments.

You gotta do

Once upon a time, night flying was one of my very favorite things, and the more hard-core, the better. A night instrument take-off (ITO) into low hanging pitch black clouds was my cup of tea. Climb to the flight levels, maybe shedding a little ice along the way? Even better. Make a long run solid in the clouds (IMC) with a dead nuts (called that because nutsing it up would get you dead) approach to absolute minimums. Then finish it off touching down on a rain or snow-swept runway that appeared out of the mists at 100 feet. (Yes, one could go that low on an ILS if, at 200 feet, the runway threshold was in sight.) Now that's a pizza!

I really liked night flying but, for some reason, night sailing? Not so much. Which is a little weird since we liked sailing at night on our little lake. Since coming “out here” though, night sailing hasn't been near the magical fun it was at Carlyle.

Just a bit of color on this night sail though we had expected a glorious sunset.

I'm trying. We keep doing overnight runs partly because there is little choice if one wants to get to the Islands in the fall. Daylight is in depressingly short supply. Today, where we are, the sun will set at 1705, not to return until 0645 in the morning. Nearly 14 hours of darkness. Making any kind of distance means sailing at night. Besides, serious cruisers, even coastal ones, make multi-day runs and, someday, I would like to be taken for a serious cruiser. So sailing at night is something we just need to do.

We did one last night as part of our Oriental – Beaufort – Masonboro – Wrightsville Beach run. So far as night passages go, it was as benign as could be. Perhaps a bit too benign as there was little wind and we motored the majority of the way. Fortunately the tiller pilot mod to the Cape Horn wind vane was working pretty well. A nice surprise since it, literally, works on a shoestring. The sky over Kintala was clear and, though there was little moon, lights reflecting off the clouds over the distant shore made it less dark than it could have been. It should have been an easy passage. It was an easy passage. But I still could not wait until it was over.

I keep trying to figure out why. A lot of esoteric explanations come to mind, but none of them really matter. I just don't like sailing at night. Really though, last night had its charms. No one gets the view of the night sky that a sailor gets. There is no windshield in the way, no ground lights, just stars and planets wheeling overhead horizon to horizon, punctuated by the occasional meteor streaking across one's sight. Nothing will make one feel as small on the one hand, or as grand on the other, as seeing the cosmos laid out in all of its glory. There is barely a spiritual bone anywhere in my body, but I couldn't help wonder if my dad is out there now, a part of the mystery, and whole once again. One doesn't get that kind of healing on land. Sorry.

All things considered did a pretty good job. The stern nav light came a cropper with traffic closing in from behind. Some duct tape and a dinghy light got us visible once again. With the auto-helm working, the on-watch person could sit in the dodger while the off-watch person slept below. A huge improvement from sleeping in the cockpit when not standing at the wheel for hours at a time. The Masonboro inlet was new to us, but there was no way to time the trip to get us there in the daylight. So, as much as we wanted to be done with the hook down, we made the call to idle around the “A” marker until the sun was up enough to see. Masonboro is an easy inlet, but it was the right call to make.

The Wrightsville Beach anchorage

A walk to the beaach at Wrightsville Beach

And now we are tucked deep into the anchorage at Wrightsville Beech. There is some weather due to start building tomorrow night, so we will likely be here a few days. We liked this place when we came through here two years ago, but didn't stay long enough. We hope to remedy that this time around. It is also a chance to work the Dink and the Merc a little, both of which have been sitting idle for too long. And we are back, laying to an anchor in a pretty place. Which is why we came this way in the first place.

Then, like it or not, more night sailing will be required to keep on moving south.

You gotta do what you gotta do.