Visit our Popular Forums

**SV Someday Came** · 21-02-2008, 18:03

Hello

Is there a web site that offers approximations of time of passage to various destinations? My boat supposedly does 5/6 knots. I want to get a rough estimate of the time it takes to get from Los Angelas to Cabo San Lucas to the Marquesas to the Cooks to Hawaii and to LA.

I am not counting stays or delays and I know weather is a factor; however, I just want a rough guestimate and I hoping to find a resource that can teach me how to consider time and distance. I cannot seem to get my arms around the time passages take since people make extended visits to different places. I guess this paragraph is a round about way of asking no one to take me to task for not being precise enough in my question.

Thanks

Michael

ssullivan · 21-02-2008, 18:07

If you find this, I'd be very interested in it. Hey Jay, from Alaska... here's your idea!

I have looked for one many times, and only found "as the crow flies" calculators that only went between major cities. We need a site that you can put in lat/lon and it will plot a rough course over water only, arriving at a total NM distance.

Can you say "applet", Jay??

jrd22 · 21-02-2008, 18:33

Unless I am misunderstanding your question, isn't it a simple matter of dividing the distance by the anticipated boat speed, and then adding in a fudge factor of maybe 15% - 20%? Or are you trying to find the distances?

John

ssullivan · 21-02-2008, 18:38

Yes, it's the distances, John. If you don't have the charts handy for a route you've never done, but are interested in doing, it sure would be nice to be able to select a start and and end from a map of the world, and have some software do a great circle route that would account for land masses you'd have to avoid.

Charlie · 21-02-2008, 18:56

Have you looked at a globe or an atlas. Many of them have shipping routes for major ports. From there an approximation can be made by multiplying boat speed times 24 hrs and then multiplying by 75% to 85%. This will give you an approximation.

dana-tenacity · 21-02-2008, 19:04

Quote:

Originally Posted by MV

Hello

Is there a web site that offers approximations of time of passage to various destinations? My boat supposedly does 5/6 knots. I want to get a rough estimate of the time it takes to get from Los Angelas to Cabo San Lucas to the Marquesas to the Cooks to Hawaii and to LA.

I am not counting stays or delays and I know weather is a factor; however, I just want a rough guestimate and I hoping to find a resource that can teach me how to consider time and distance. I cannot seem to get my arms around the time passages take since people make extended visits to different places. I guess this paragraph is a round about way of asking no one to take me to task for not being precise enough in my question.

Thanks

Michael

I did most of these in a 32 ft boat that averaged about 120 miles per day over the years (no motoring).
LA to Cabo non-stop 7-10 days. about 1000 miles
Cabo-Marquesas 25-30 days about 3000 miles but with luck an easy downhill slide
Marquesas- Cooks who cares, relax and enjoy. OK 2 weeks at a guess.
up to Hawaii- if your boat goes uphill like a race boat 3-4 weeks. 3000 miles or thereabouts.
Hawaii-LA you have to go a long way north first, I'd say 3 weeks to SF (never done Hawaii-LA).

**SV Someday Came** · 21-02-2008, 19:30

I did not think of looking for shipping routes in an atlas. And I figured that currents and wind would help in some directions but not in others, so maybe strict distance by speed might be misleading -- and I had no clue as to how to estimate a fudge factor. Having no experience in an area makes it tough to ask the right questions. That being said, this information helps alot. Thanks!

Michael

rebel heart · 21-02-2008, 22:04

Don't know how this one got missed:

Amazon.com: World Cruising Routes, 4th Edition: Books: Jimmy Cornell

MarkJ · 21-02-2008, 22:13

Quote:

Originally Posted by rebel heart

Don't know how this one got missed:

Amazon.com: World Cruising Routes, 4th Edition: Books: Jimmy Cornell

By the price.

Its an expensive book. I want one though. Anyonewannagivemetheres?

Troutbridge · 22-02-2008, 01:14

Try using your GPS (assuming you have one). Create a start and end position, most GPSs these days allow you to input a planned speed and there's the answer.
One reason trips can take longer than seems reasonable is the need to avoid cyclone seasons. I strongly suggest you get Cornell's book. If you're planning any water sailing">blue water sailing and the price of the book is a deal breaker I have to say you probably can't afford to go!
Seriously, if you can't 'get your arms around' the concept of speed, distance and time taken you need to do a bit of studying. Well, a lot actually, knowing how long a trip might take is pretty well crucial, taking an appropriate amount of food, water etc.

**GordMay** · 22-02-2008, 01:28

I deeply regret leaving my copy of Cornell’s “World Cruising Routes” aboard “Southbound”, when we sold her. A great book.

The National Geospatial-Intelligence Agency (NGA) has several free publications.
Maritime Safety Information

Pilot Charts are intended to aid the navigator in selecting the fastest and safest routes, with regards to the expected weather and ocean conditions.

The Atlas of Pilot Charts
Maritime Safety Information

**Hud3** · 22-02-2008, 02:39

Quote:

Originally Posted by Charlie

Have you looked at a globe or an atlas. Many of them have shipping routes for major ports. From there an approximation can be made by multiplying boat speed times 24 hrs and then multiplying by 75% to 85%. This will give you an approximation.

For estimating average boat speed, Charlie's suggestion to multiply your boat's hull speed by a factor is a good one. In my experience (maybe 12,000 nm), I'd use 75% of hull speed.

It might be worth it to you to invest in some software. I use CMAP PC Planner, which allows me to plan routes on my computer using the CMAP NT cards from my chartplotter in a USB cardreader attached to the computer. I can work out a float plan, with alternatives, and then download it to the chartplotter for the actual passage.

You really should get a copy of Cornell's book to help you decide which routes are best for you on long ocean passages.

ssullivan · 22-02-2008, 05:20

I have "World Cruising Routes", but at this very second it's still in storage while I await delivery of my new boat.

From what I reacall, it shows you routes, but doesn't say exactly how long a given route is, plus what if your route isn't specified in the book?

Also, I never had an atlas on a boat, due to self-imposed weight restrictions (we have a fairly small "library" on the boat). However, having an atlas sounds like a pretty good idea. There is likely a scale somewhere on the map that you can use your dividers with for a fairly accurate rough estimate.

Lastly, using a GPS doesn't work at all. Say you were going from Greece to Brazil. Plug those both into a GPS and you're off by hundreds if not thousands of miles. There are plenty of sites that allow you to do "as the crow flies" distances, but they do not account for the fact that you can't sail over land.