ICW TABLET NAVIGATION Charts on the ICW
July 12, 2019
There has been a sea change in small craft navigation over the past few years. Today boats circumnavigating the globe with a tablet as their chartplotter. For those of us cruising the ICW the changes are no less revolutionary! The impact of tablet navigation apps will affect cruisers differently based upon their experience, their existing navigation tools, and the cruising grounds.
Most ICW cruisers have an installed chartplotter. Tablet navigation allows you to scan the area ahead and around you looking for new options and destinations, while the chartplotter continues ... Read More
This section of the ICW is called the “South of McClellanville” section. It is one of the longest and shallowest trouble spots on the ICW. The following is an overview of this stretch of the ICW between Awendaw Creek and Jeremy Creek. While there are some places with 8-10 feet of water, there are also stretches with less than 5 feet of water at MLLW. If you drift out of the “channel” you will find water less than 3 feet. So, what defines the channel? How do you find it?
We transited this section for the eleventh time on March ... Read More
For some reason the section between STM 717 and STM 719 is confusing to some. It needn’t be.
Northbound after exiting Kinglsey creek you are in the Amelia River. Stay to the east side past R2. The charts show the deepest water on the lower east side. I have used the upper west side at the G2 bend of the river for about 5 years, as the water is deeper along the western shore The eastern channel has at least 8 feet of water at MLLW. The western channel has 12+ at MLLW . This is one place you ... Read More
A significant shoal has been growing at R12 and R10A. The picture below is from Aqua Map with the USACE survey of March 6, 2019. We drifted off center because we were being passed buy a 55’ motor yacht right at the worst section. He did not have these USACE charts and was not aware of the shoal. He was quite surprised to slow down and suddenly realize he was in very shallow water. The water was so shallow the motor yacht could not accelerate onto plane until the water got deeper in about 100 yards east. We had ... Read More
The ICW path through the new River Inlet has changed over the past few years. Starting in 2016 it now includes a “dip” at R72A. The path between R70 and R76 is now called the “Dip Route”. The marks can be confusing, and the stress is compounded by strong cross setting currents.
Southbound, R12 and R12A add to the confusion. They mark the New River Inlet Channel and are not part of the ICW. They have however caused great confusion. R12A is in direct line with ICW R70 and R72 which leads some southbound boats to pass R72A to port ... Read More
There has been a shoal building off R86 about 8 miles north of Isle of Palms. The NOAA charts do not provide enough detail to help you know which side of the shoal to pass. Most guidance says to stay east of the shoal. We have made several trips on the west side of the shoal. In looking at the Aqua Map Master USACE surveys as we planned our route last week, the surveys have no information on water depths east of this shoal. Based on that decided to go west of the shoal March 31:
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- We have tracks of
The 6 NM stretch of the ICW behind Isle of Palms has about 9 channels between the marshes and the ocean which cross the ICW. Each of these crossing has the potential to create shoals. If you look at the attached screen shots, you can see that each of these inlet crossings has developed the classic pattern of shoals on the ocean side which results in the M shaped route you must follow as you pass many inlet crossings along the ICW.
Although it was dredged in early 2015, we have noticed that this shoal stretch is getting worse with ... Read More
This has been a tough ICW trouble spot for the past couple of years. Dredging has just been completed (there are pipes and barges still onsite) and the channel marks have been reset. As of today, it is a simple straight shot. Just stay between the markers for 12-14 feet at low tide. I can attest to the low tide depth, we came through at dead low this afternoon.
We are using 4 different charting and navigation systems. We have NOAA charts running on a PC, Navionics charts in the Raymarine chart plotter, Navionics sonar charts in an iPAd. And ... Read More
There is no official source (NOAA, USCG, USACE) which suggests that the magenta line should be treated as a chartplotter route.
The ICW was laid out in 1913. Chartplotters were not very accurate 100 years ago! To aid pilots running down the coast, a magenta colored line was drawn on the charts to indicate which rivers, creeks, sounds and canals were all interconnected to provide an inshore route between the Chesapeake and FL. The Magenta line was merely like Hansel and Gretel’s bread crumbs. It is merely a means to find the path. The captains in those days monitored their
We have traversed this section 4 times in the past 2 years. We use NOAA charts updated daily in Coastal Explorer and we use Navionics Sonar Charts. For some reason the NOAA charts in this intersection are all dated 2015. I am not sure why the charts on the NOAA site have not been updated. But Navionics Sonar charts have steered us through here every time with no issue. And while Aqua Map base maps are NOAA (and show the NOAA 2015 charts), they have recently added the USACE surveys as part of their Aqua Map Master app. The USACE ... Read More