[Rhodes22-list] Magnetic or True?

[Bill Effros]

Rory,

People just starting to sail don't understand what makes this such an 
interesting question.  Obviously, you can't use a steering compass and 
chart plotter using true at the same time if you don't also understand 
the concept of magnetic declination.  In fact, if you are traveling long 
distances, you can't even use a steering compass and a chart plotter 
using magnetic if you don't understand that the compass is not 
necessarily pointing toward the magnetic north pole.

Furthermore, the chart plotter is telling you which way the boat is 
moving, not which way it's pointing, or what is the best direction to 
point in order to arrive at your destination in the shortest amount of time.

Now it is true that you can derive much of this information from a 
GPS--but not if you don't understand the question.

For me, the sextant is the greatest navigational tool ever invented.  A 
GPS is nothing more than a sextant with a super accurate clock built in, 
and the ability to do the site reduction automatically.  There are 
sextants available now with automatic site reduction.  The problem with 
the GPS is that governments have retained the ability to deliberately 
throw off the clocks in the satellites, and they intentionally do so 
from time to time.

Sextants are harder to use, but if you have ever been with a navigator 
who is good with a sextant it is a thing of beauty to behold, and well 
worth learning.

Bill Effros



Rory Orkin wrote:
> When I am using the chartplotter I use True.. But I could make the case also
> for Magnetic as well if I am going to rely on the compass once plotted.
> Probably not much help but an interesting question
>
> Bill Effros wrote:
>   
>> Rory,
>>
>> Do you chart magnetic or true?
>>
>> Bill Effros
>>
>>
>>
>> Rory Orkin wrote:
>>     
>>> I think a charting GPS is the greatest navigational tool ever invented..
>>> It
>>> gives you an accurate fix instantly and reports your speed as well. If
>>> you
>>> get one that interfaces with the radio it will broadcast your position in
>>> the event of a Mayday.
>>> Not likely but when you want it,  the best piece of information you can
>>> have
>>> is your exact position. The GPS is the best way to come up with that
>>> quickly
>>> and precisely
>>> That being said I always use my paper chart book because it gives a much
>>> larger perspective on where you are and where you want to go..not to
>>> mention
>>> giving a better overview on hazards..
>>> The compass is also essential for an easy way to maintain a heading or to
>>> tell someone else how to point the boat.
>>>
>>>
>>> Frazier Scott wrote:
>>>   
>>>       
>>>> I plan to have my new rhodes 22 this spring.  I will be sailing on Long
>>>> Island Sound.  I will add a VHF radio and a compass but wonder what else
>>>> by way of navigation equipment I should have.  A GPS seems to be
>>>> advisable, but is it necessary?  What type of compass is best and where
>>>> should it be mounted?
>>>>   Any advice is helpful.  (Rummy, I expect to stock Mount Gay, so I have
>>>> that covered).
>>>>   Thanks,
>>>>    
>>>>   Frazier Scott
>>>> __________________________________________________
>>>> Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>>>>
>>>>
>>>>     
>>>>         
>>>   
>>>       
>> __________________________________________________
>> Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>>
>>
>>     
>
>