Savannah to St Augustine

[TPG]

Fairly new to navigating and ran into a head scratcher using chartplotting software. Route from Savannah to St Augustine on the ICW shows right at 156nm and 30 hours. Going the outside route shows 124nm but 42 hours.

Same speed, nothing different. Should be quicker going outside I'd think...right?

[Sparx]

Your outside route works our to somewhere around 3 knots. Most boats will do this run much faster than 3 knots, unless the chosen route is against the gulf stream.

For planning purposes route Savannah to St Augustine out in the ocean at about 60 foot depth line and the boat should be well out of the gulf stream .

[a64pilot]

The Gulf Stream is WAY off shore in that area

[Snore]

The BIGGEST difference is if you go outside, you don’t have to deal with the twists and turns of the ICW. Set the AP, make a coffee and enjoy the ride.

[a64pilot]

It also gets real shallow just South of Brunswick, if you draw more than about two feet you need to do that section close to high tide.

[OutOfControl]

The National Weather Service Marine Forecast in my area includes Gulf Stream location data. It's roughly 60 miles off shore from Jacksonville and St. Augustine.


https://www.ndbc.noaa.gov/data/Forec...US52.KJAX.html

[Sparx]

Yes the gulf stream is way off shore between Savannah and St Augustine. One would have to go way further OUT than the most logical routing. Does anyone have another suggestion on why the router TPG is trying out would get a much slower over ground speed out in the ocean versus in the ICW?

To address the original post, I would think the outside route would be much faster. I agree with Snore, off shore is a simple cruise without all the turns of the ICW. With good weather offshore would be a pleasant cruise, and for many boats the speed over ground likely much faster sailing in the ocean versus motoring in the ICW.

From a practical standpoint I think of the ICW as a travel only in daylight route requiring 3 to 4 days. Off shore would off course be around the clock and about 1 day.

[sailorboy1]

I’ve done it both inside and outside. It of course is fewer days to do it outside even if you motor all way. I definitely wouldn’t night travel that section of the ICW. If you plan to day sail the outside route add lots of extra distance for going in/out.

Personally except to visit Beaufort SC the only reason to do that trip is because the outside weather is going to be bad for it for 5 days and you just want to make distance.

[Lodesman]

Originally Posted by TPG

Fairly new to navigating and ran into a head scratcher using chartplotting software. Route from Savannah to St Augustine on the ICW shows right at 156nm and 30 hours. Going the outside route shows 124nm but 42 hours.

Same speed, nothing different. Should be quicker going outside I'd think...right?

I think we would need to know more about your software, and what variables you put into it. Basic software would make a simple speed/time/distance calculation - perhaps yours makes a distinction between smg sailing and motoring??

[Daniel Grant]

The inside can be a beautiful lazy trip. There are some sections if you folow the chart plotter you will be on the bottom. at Jekyll you need to do that section at better than 1/2 tide and the Medway River stretch at at least 1/2 tide.If you plan on coming in at St. Augustine do so very carefully it is not an easy inlet to navigate coming in.

[gonesail]

That part of the ICW in GA is very tough. Huge tides and currents with shallow areas. I did it this summer and ran aground twice. Also St. Aug inlet is a big challenge. One man's opinion.

[jkleins]

What is the challenge of the St. Augustine inlet? It seems like a straight shot with good depths since they dredged. Is your opinion new or based on before dredging?

[LoudMusic]

We did this recently and were in a bit of the counter flow with a stiff north wind. We were hitting upwards of 10kts SOG with just the asymmetrical out on our 43' cat. Racing down the massive swells was ... exhilarating.

Hug the coast (2-5 miles out). Don't get into the northbound gulf stream. You'll boogy offshore.

[sjm823]

Jkleins-
The St. Augustine inlet is not really treacherous as long as one follows the straight line from sea buoy to the channel markers. Don’t take a short cut and curve toward the inlet from either north or south, as there are shallows on both sides that extend far out into the ocean. Another “problem” with St. Augustine inlet is a rapid outflow from the Intracoastal meeting the incoming ocean tide; there is lots of turbulence.

[zboss]

Originally Posted by jkleins

What is the challenge of the St. Augustine inlet? It seems like a straight shot with good depths since they dredged. Is your opinion new or based on before dredging?

Our inlet has shifting shoals and swift currents.

The currents that intersect with the ICW can be quite swift and easily push you out of the channel when you are just inside. You need to be looking forward AND backward to make sure you are getting pushed sideways. If coming down the ICW from the north there is a shoaling area just west as you reach the intersection with the inlet. Boats run up on that all the time.

On the outside, the army corp continually dredges sand and puts it north onto Vilano to save the expensive houses and the popular destination beach where it is promptly swept south and out into the channel again. There are proposals to stop dredging and allow the inlet to return to its natural state.

Our markers are often off station after storms and they have been know to catch those unfamiliar with the markers off guard. We had at least 5 boats go up on the shoals this year.

It sounds worse than it is... you just need to be very careful and never enter/leave the first time at night.