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XTREME MJ survives Hurricane Irma! Read one customer's experience (September 2017):
"We've owned a Bad Boy (Xtreme) MJ for about 3 years now, and it has been a highly valuable device on board. We've got it installed at the top of the mast, riveted in on the provided L bracket. We are located in St Maarten where we recently took a huge Category 5 direct hit with over 200MPH/360KPH winds. I'm happy to report the Bad Boy, with antenna, is still mounted at the top of the mast. Suffice to say, your product is pretty robust. Thanks again!" - Derek, s/y ARAVILLA

If you can find a better price for a complete system similar to Xtreme, we will better it by 10%!
Practical Sailor "We think it’s a good value for a high-quality product"   Read...
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Nautical Calculator for Windows XP, Vista, 7, 8, 10


Product Description

*** FREE ***


Nautical Calculator provides an array of powerful functions for those learning marine navigation or want to reduce the amount of pencil and paper math and increase reliability and accuracy of their calculations when planning a voyage. Version is for Windows XP, Vista, 7, 8 and 10 only. No software registration key is required. Free to share.


  • Easy to use
    Intuitive, clean, and professionally designed to speed up usage and minimize typing.

  • Latitude/Longitude from Coordinate, Bearing and Distance
    A destination coordinate can be determined if you know the starting coordinate, the true bearing and the distance.

  • Bearing and Distance Between Two Coordinates
    Enter an origin and destination coordinate and see what the initial true bearing and distance are.

  • Determine Set and Drift
    Enter your deduced reckoning (DR) position and your actual position and let Nautical Calculator compute the set and drift.

  • Course to Steer
    Enter your desired course, planned speed, the set and drift and let Nautical Calculator determine your course to steer (CTS) and speed made good (SMG).

  • Distance and Speed Calculations
    Standard distance and speed calculations.

  • Estimated Time Enroute (ETE) and Estimated Time of Arrival (ETA)
    If you know the distance to be traveled and the speed, you can determine the estimated time enroute (ETE) and the estimated time of arrival (ETA). Of great benefit is the display of days, hours and minutes for ETE and date and time for ETA.

  • Distance to Horizon and Feature
    When making a passage, it is sometimes useful to know how far out you will be able to see landfall. Knowing your elevation above the water and the height of the distant feature, Nautical Calculator can easily determined this.

  • Latitude/Longitude Conversions
    Convert between a number of different real world coordinate formats  (degrees, degrees/minutes, degrees/minutes/seconds).

  • Time Calculations and Conversions
    Convert 12 hour to 24 hour format. Add and subtract hours and minutes up to 24 hours. Result displayed simultaneously in both local and Greenwich time.

  • Sun/Moon Rise/Set
    Shows the times for sunrise, sun transit and sunset for any day. Provides three twilight start and end times: civil, nautical and astronomical. Also shows the moon's rise and set times. Times can be shown in either local or Greenwich time.

  • Moon Phase
    A calendar with the phases of the moon for each day is displayed. The New, Full and even Blue moon dates are highlighted.

  • Beaufort Scale
    To facilitate understanding of weather reports which include a Beaufort Scale value, this screen provides descriptions for both at sea and on land for the full range from calm (0) to hurricane (12).


Operating System:
Windows XP, Vista, 7, 8, 10
.Net Framework 3.5

Product Reviews

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Showing reviews 1-5 of 6 | Next

  1. Fine Product

    Posted by piero on 12th Mar 2016

    Good product, working fine

  2. Great Product - thank you

    Posted by Clay on 18th Mar 2015

    I'm impressed by the breadth of your free offering - thank you

  3. excellent quick check

    Posted by Unknown on 29th Jan 2015

    Does much of its work using meridional parts, which is a drawn out affair. Very easy to use.

  4. Best I have seen so far

    Posted by Luis Castro on 6th Jan 2015

    I am able to do those calculation using trigonometry, this will give me the same answers without having to go to those lengthy formulas.

  5. Great easy to use PC app.

    Posted by Alf Burnham on 8th Jul 2014

    Great little addition to my PC. Preforms a bunch of interesting calculations and lookups. Be nice to have Mafor decode in a future version.


Showing reviews 1-5 of 6 | Next

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