Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 27-08-2021, 13:31   #1
Registered User

Join Date: Aug 2021
Posts: 12
Advice needed

Hi all. Im hoping I can get some help with plotting a course from Miami to Costa Rica in a 46 Egg Harbor twin 671s. I think my first port will be Isla Mueheta Mexico but from there im not sure the better route to go. any info from those who have done this is greatly appreciated.
trckdrivr is offline   Reply With Quote
Old 27-08-2021, 13:38   #2
Registered User
 
Sailmonkey's Avatar

Join Date: Sep 2009
Location: Houston
Boat: ‘01 Catana 401
Posts: 9,626
Re: Advice needed

What’s your range?
Sailmonkey is offline   Reply With Quote
Old 27-08-2021, 13:47   #3
Registered User

Join Date: Aug 2021
Posts: 12
Re: Advice needed

As of right now I’m guessing 400-450 no. She just picked this boat up, and was told she’ll cruise 10-12 kts comfortably, she has twin 250 gal fuel tanks and will probably carry an extra 100 gals as emergency fuel.
trckdrivr is offline   Reply With Quote
Old 28-08-2021, 05:13   #4
Registered User
 
ranger58sb's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 58' Sedan Bridge
Posts: 5,420
Re: Advice needed

FWIW, I'd be leery about 400-450 NM range at that speed range except maybe in ideal circumstances, or at slow "trawler" speeds (which might work fine).

First, the 400 figure would need .8 NMPG all in, i.e., with no reserve... not counting extra reserve fuel on deck... and I doubt that'll happen on those DDs at that speed range. (Are they 485 HP? Can't remember DD numbers...)

Second, I suspect 10-12 kts would probably be a very inefficient speed range, probably pushing a lot of water. I'd have guessed comfortable cruise on plane would maybe be more like 16-18 kts.

Anyway, the waterline length is likely more like 40' -- so maximum theoretical displacement hull speed would be about 8.47 kts. (Have to refine that, based on true waterline length. Formula is 1.34xSQRT-LWL)

Best fuel economy would likely be somewhere between 6.32 kts and 7.59 kts (1.2x).

Given GPH/engine at a given RPM, and once you know what RPM gives what speed, you could figure range at 7.5 kts with a built-in fuel reserve of 10% or whatever.

-Chris
__________________
Chesapeake Bay, USA.
ranger58sb is offline   Reply With Quote
Old 28-08-2021, 05:45   #5
Marine Service Provider
 
Snore's Avatar

Join Date: Jan 2011
Location: St. Petersburg, FL
Boat: Retired Delivery Capt
Posts: 3,684
Send a message via Skype™ to Snore
Re: Advice needed

Mami>Stock Island Marina (this run will also serve to verify fuel consumption)

Assuming the range is verified

Stock Island >south of GS> Then west to Isla Mujeres
Isla>Roatan
Roatan>???
???>Costa Rica

Has the diesel computer been integrated into the NMEA data stream? If there is a realtime GPH or MPG readout it would be easier to verify fuel consumption.
__________________
"Whenever...it requires a strong moral principle to prevent me from deliberately stepping into the street, and methodically knocking people's hats off- then, I account it high time to get to sea..." Ishmael
Snore is offline   Reply With Quote
Old 28-08-2021, 05:52   #6
Registered User
 
ranger58sb's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 58' Sedan Bridge
Posts: 5,420
Re: Advice needed

Quote:
Originally Posted by ranger42c View Post
I'd have guessed comfortable cruise on plane would maybe be more like 16-18 kts.

Best fuel economy would likely be somewhere between 6.32 kts and 7.59 kts (1.2x).

I meant to mention slow speeds with that type of (planing) hull may not always be comfortable, especially depending on sea states.

IOW, not a recommendation, just observations.

-Chris
__________________
Chesapeake Bay, USA.
ranger58sb is offline   Reply With Quote
Reply

Tags
Advice

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tax Advice Needed - Sailing Advice Given mparent General Sailing Forum 0 12-07-2010 07:16
Engine advice needed!Volvo MD3//Yanmar 3QM30 geoleo Engines and Propulsion Systems 0 22-04-2007 09:28
EUREKA!! (but advice needed) ssullivan Monohull Sailboats 38 10-04-2007 21:27
Autohelm 3000/4000 advice needed boatclassic Marine Electronics 10 11-02-2007 00:22
I have bad tasting water - advice needed markvanniekerk Cooking and Provisioning: Food & Drink 24 08-02-2007 23:31

Advertise Here


All times are GMT -7. The time now is 12:23.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.