Old Boater - Switching to Statute Miles/MPH vs Knots/Nautical Miles???

Maybe A Dancer

Maybe A Dancer

Became a Dancer 12/23/21
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Aug 20, 2021
1,312
Florida West Coast
Boat Info
Started out as MAYBE A DANCER
Became a Dancer - 12/23/21
Engines
450 DA Sundancer running CAT 3126
been boating over 30 years.

started with paper charts, and still keep them onboard.

All this time I've used KTS/NAUTICAL MILES in all calculations and record keeping.

Doing a lot of cruising now, running AQUAMAPS alongside my chart plotter.

When running the intracoastal waterway everything is listed/shown as STATUTE MILES, not nautical miles, INCLUDING The posted ICW distances on the paper charts.

Numerous other cruisers, specifically in AGLCA have strongly suggested that the only way to run THESE DAYS is to switch the chart plotters over to STATUTE MILES/ MPH.

Thoughts?

BEST !

RWS
 
I run both. I have two plotters, one showing nm and the other miles. Kinda silly...but it suits me.

Since almost nobody actually reads paper charts any more, nautical miles have substantially lost their usefulness in my opinion.
 
I’ve always used s miles. Karen has always blogged our loop, Bahamas, and other trips. The rest of the world that might be reading those blogs has no idea what a knot or a N mile is.
 
Knots and nautical miles is still the standard reference for aviation and marine use. Statute miles may be useful when navigating inland rivers and the ICW because of the use of statute mile markers. I use nautical miles.
 
Guess that's me.

But............... all the distances are marked in statute miles.

I'm thinking the right move would be to switch over to statute miles for speed and distance.

Guess TIME will stay the same :)

Interested to hear compelling comments either way

BEST !

RWS
 
I am in hard core agreement with Blueone on this issue.

After having used both for so long, it really doesn't matter to me. Over time, one becomes used to guesstimating the difference with enough accuracy to be able to fake it. I will admit though, in the beginning as a kid and having learned nautical, the fact that speedometers seemed to always be in statute miles, created a PIA. Although, that also may be how I learned to quesstimate the difference.

Throw metric in the mix, and I'd be as confused as on Day 1.
In spite of fact both have been in our cars for decades now, I never cared or payed any attention to the metric part of that. That obviously wasn't the case as a young man wanting to get offshore.
 
Since I relate better to mph or just miles, I have never used knots. Plus I don’t want to do the math every time I think about knots. Not really a compelling reason but that’s why I choose miles.
 
I think you pretty much answered your own question. If I look at this from your point of view and what you've written... with all (or at least most) of the data you have at hand for calculations/etc is coming to you in S miles, it just makes sense to select the other checkbox on your plotter for Statute. That way everything jives. Besides, in the end, it's just two different means to an end... or "course" in this case :)
 
Isn't a nautical mile equal to one minute of latitude around the equator?
If I was using a sextant for navigation then it seems to me that I'd need to use nautical miles.
Since the rest of the world around me is statute miles I use that.
 
Maybe A Dancer said:
But............... all the distances are marked in statute miles.

I'm thinking the right move would be to switch over to statute miles for speed and distance.
Click to expand...

We use knots and NMs.

Haven't found the statute mile markers on the AICW anything more than occasionally mildly interesting. In fact, they're usually only virtual markers on the plotter these days; not as many physical mile markers as there used to be. We rarely bother to mentally convert, mostly because it makes no difference along the way.

Nor do we usually care much about speed or distance, partly because we often prefer to do short legs at slow speeds.

I'd suggest since you're used to using knots and NMs, leave it that way for your first AICW trip and then decide afterwards if you care or not.

-Chris
 
For me nautical miles mean nothing, knots mean nothing, airline pilots that means something too. For the reason Tom mentioned.

I use statue miles for everything, as mentioned the nautical world around us doesn't use nautical miles for anything. All speed limits are in mph on the water, that should tell you something.
 
ttmott said:
Isn't a nautical mile equal to one minute of latitude around the equator?
If I was using a sextant for navigation then it seems to me that I'd need to use nautical miles.
Since the rest of the world around me is statute miles I use that.
Click to expand...
A nautical mile is equal to one minute of latitude everywhere on earth. The length of a minute longitude varies depending distance north or south of the equator. This is why distances on a nautical chart are always measured using the latitude scale. Understanding nautical miles is fundamental to any kind of navigation except electronic. It's also useful in maneuvering as well as communicating with commercial traffic.
I learned how to navigate as well as maneuver using knots so can't imagine operating any differently. But, since most all navigation is done by electronics these days, I can certainly see why folks brought up using statute measurement would stick with what they know.
 
Skybolt said:
All speed limits are in mph on the water, that should tell you something.
Click to expand...
Orlando, this bothered me since I was sure all the markers around the Chesapeake (or anywhere else I have been) I have seen show speed limits in knots. I checked, and Maryland's water speed regulations are expressed in knots. See https://dnr.maryland.gov/boating/Pages/regulations/changes_boating.aspx.
However, I don't think the delta between systems is going to make a whole lot of difference to your wake or whether you will get a ticket. In fact, if you're observing the typical 6 knot speed limits we see around here by going 6 MPH you are always going to be under the limit.
 
alnav said:
A nautical mile is equal to one minute of latitude everywhere on earth. The length of a minute longitude varies depending distance north or south of the equator. This is why distances on a nautical chart are always measured using the latitude scale. Understanding nautical miles is fundamental to any kind of navigation except electronic. It's also useful in maneuvering as well as communicating with commercial traffic.
I learned how to navigate as well as maneuver using knots so can't imagine operating any differently. But, since most all navigation is done by electronics these days, I can certainly see why folks brought up using statute measurement would stick with what they know.
Click to expand...
So, a nautical mile at the North and South poles is zero in length??
I seem to remember it is consistently one minute at the equator. But, It's been years, like 40, since the schooling....
 
ttmott said:
So, a nautical mile at the North and South poles is zero in length??
I seem to remember it is consistently one minute at the equator. But, It's been years, like 40, since the schooling....
Click to expand...
No, 89 degrees 59 minutes north is one nautical mile south of the pole. I believe you are remembering longitude, which is one nautical mile per minute at the equator but approaches zero length at the poles.
 
alnav said:
Orlando, this bothered me since I was sure all the markers around the Chesapeake (or anywhere else I have been) I have seen show speed limits in knots. I checked, and Maryland's water speed regulations are expressed in knots. See https://dnr.maryland.gov/boating/Pages/regulations/changes_boating.aspx.
However, I don't think the delta between systems is going to make a whole lot of difference to your wake or whether you will get a ticket. In fact, if you're observing the typical 6 knot speed limits we see around here by going 6 MPH you are always going to be under the limit.
Click to expand...

Everything in the Narrows is mph or at least the marine police use that instead on knots. As you know the current there is fast somewhere ~8-10mph at times. Last yr. I was going with the current and had to go upwards of 9mph to be able to navigate, got pulled over and the police only spoke in MPH. But to your point 6knt's = 6.9mph.
 
I am constantly switching from metric to inch at work…. Some customers are metric some are inch…. It’s an insane pain in the ass…. But it is what it is…. I’m sure you guys can figure out nautical mile, knots and mph it’s not that hard
 
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