Gulf Stream crossing comfort

All, we are sitting in the Bahamas and looking to cross back to the US from marsh Harbour. Our destination will be Fort Pierce. Our boat is a 46 footer. We will be traveling at about 8 kn, and have hydraulic stabilizers.

This will be our second crossing in this boat. As former sailboaters, we always paid attention to see State, but this boat is not as salty as our sailboat. As I look at wave height versus period In the golf stream, I am wondering if a wave period twice that of the height will be comfortable in the stream. If waves are predicted out of the north at 3 feet will I be comfortable with a six second interval, or should I avoid all northerly waves?

In sights would be appreciated...

Thanks
Gordon

with 3 foot predicted, an occasional 6 footer is to be expected.

http://www.nws.noaa.gov/om/marine/faq.htm#14

Thanks

psneeld said:

with 3 foot predicted, an occasional 6 footer is to be expected.

National Weather Service Marine Forecasts - FAQ

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Psneed, I understand that part, I guess I don’t understand what it means to be in the Gulf Stream with predicted 3-footers and 5 to 6 second interval. Is that worse than same conditions outside of stream?

I would avoid a crossing whenever the wind is out of any northerly direction. The winds here normally "clock" in changing direction, north now, NE tomorrow, and then east, then SE. I have been across in as small of a boat as a 26 center console and up to 110 feet, in your 48 foot boat at 8 knots I would suggest to wait. The boat might take the waves fine, it is the people on board that might suffer.

Tucker, thanks. I am using Windy to find an optimal day. We are setting pretty at Abaco Beach Resort and are not required to move — Nice part about being unemployed. Waves are supposed to be from the south in the Gulf Stream on Sunday, even though it is supposed to rain all day. That may be our best bet, or wait another week...

Actually you got it correct...northerly winds in the Stream just mean a steeper wave, one with less period.

so northerly or not, as long as you know the steepness and probability of larger waves with that shorter period.... you got it so make your decision based on that.

Tucker, using Windy I now see that winds are predicted fierce on Sunday, so will skip that...on Monday, winds are currently predicted out of the southwest, but three foot waves from the northeast. Seems kinda odd that wind blows from southwest for two days but waves from northeast.

Thanks for your insights..

Gordon J said:

Tucker, using Windy I now see that winds are predicted fierce on Sunday, so will skip that...on Monday, winds are currently predicted out of the southwest, but three foot waves from the northeast. Seems kinda odd that wind blows from southwest for two days but waves from northeast.

Thanks for your insights..

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experience teaches that and if the predominent wave is still from the NE and the wind from the SW.... that means steeper waves and usually not much fun....

but only if the NE wave period is less than 5 sec or so, the SW wind wont stack them up much.... keep an eye on the period if you have access to that info.

Thanks psneed. Yes I have access to periodicity. Euro models predict mostly three foot -later 4 with 7 second intervals.

A 4 footer with a 7 second interval isnt bad but every 10 minutes or so you might be hit with 6 footers and a 7 second interval is pretty steep.

while certainly not dangerous, only you can make the call for comfort on a 60 mile or so crossing.

unlike many boaters I know with rudimentary knowledge of the stream, fortunately there are charts that show probable stream velocities to help determine how many miles of strong current you actually have to cross...

psneeld said:

A 4 footer with a 7 second interval isnt bad but every 10 minutes or so you might be hit with 6 footers and a 7 second interval is pretty steep.

while certainly not dangerous, only you can make the call for comfort on a 60 mile or so crossing.

unlike many boaters I know with rudimentary knowledge of the stream, fortunately there are charts that show probable stream velocities to help determine how many miles of strong current you actually have to cross...

Click to expand...

While it's temperature instead of "current", it's a pretty good proxy for where the stream is. (where it's warmer)

https://marine.rutgers.edu/cool/sat_data/?product=sst&region=floridacoast&nothumbs=0

here you go. scroll down to currents, click "add to map", then go to the top bar and click on map.

Its a MODEL, which means it's not directly measured. They use inputs (like the radars I work on) and then guestimate with a very smart computer to fill in the blanks.

https://portal.secoora.org/#module-metadata/4bc223e1-6b14-46f5-9832-f8e9ff061a36

Gabe n Em said:

While it's temperature instead of "current", it's a pretty good proxy for where the stream is. (where it's warmer)

https://marine.rutgers.edu/cool/sat_data/?product=sst&region=floridacoast&nothumbs=0

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with a range from 0 to 3, bet its current....

second one is temp....

The marina at West End, Grand Bahama is a nice place to wait for a weather window, but sometimes gets full. Call first before you go there. Freeport is an option but adds to your overall distance.

Thanks tucker

yachtbrokerguy said:

The marina at West End, Grand Bahama is a nice place to wait for a weather window, but sometimes gets full. Call first before you go there. Freeport is an option but adds to your overall distance.

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We could also wait out the weather great sale and then do an early morning departure to arrive at Fort Pierce in the evening. I am not very concerned but want to make sure that the admiral’s absolutely comfortable.

We've gone to Great Sale in the past, get in there in the afternoon, get something to eat, relax a bit, take the dogs to the beach a while, then shove off about 1800 hrs. Arrive in Ft. Pierce mid-morning the following day. If the weather's good, it's not a bad run.

Of course, if the weather's crap, well, you know how that trip goes!

I don’t understand the concern, OP is in a 46foot boat that is stablized and travels at 8 knots, seas are three feet. Sounds like a beautiful crossing to me, I wish more of mine were only three feet.

Bigsfish said:

I don’t understand the concern, OP is in a 46foot boat that is stablized and travels at 8 knots, seas are three feet. Sounds like a beautiful crossing to me, I wish more of mine were only three feet.

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Have crossed many times, sail and power. If forecast holds true for 3’ and 6 seconds from the N, then the ride against 3knot current in the stream will be very uncomfortable. Waves will stack up much higher than 3’.

psneeld said:

with 3 foot predicted, an occasional 6 footer is to be expected.

National Weather Service Marine Forecasts - FAQ

Click to expand...

Thanks for reminding me / us of the web page above Sneed. Always informative.