Knotmeter or Speedometer without hole

Discussion in 'OnBoard Electronics & Controls' started by Amateur_Expert, Apr 21, 2012.

  1. Amateur_Expert
    Joined: Feb 2012
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wichita KS

    Amateur_Expert Junior Member

    Good Morning,
    Maybe it's me but I am having a heck of a time finding anything sailboat related without the exact search terms. For example "pulley" yileds NOTHING, you have to look for "block". Also "teak handles" yields absolutely nothing but "teak handrails" are just the ticket". Maybe it's just me.

    My question is this: Is there a sailboat speedometer, speed meter or knotmeter (or knot meter) that can be installed WITHOUT cutting a hole in the boat?? Ie WITHOUT a paddlewheel? Also I don't know about thru hull or in-hull.. they sound the same to me.

    I have an older Laguna Windrose 18'. It has an old Signet Knotmeter with a paddlewheel. I want to remove it because it hits the trailer when loading (the previous owner had a lever rigged up to pull it in a little but it does not work right.

    What I would like is a speed meter that has like a transducer or something mounted to the floor of the boat without a hole.

    Any input greatly appreciated.

    Thanks

    Shawn T
    Wichita KS
     
  2. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

  3. Amateur_Expert
    Joined: Feb 2012
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wichita KS

    Amateur_Expert Junior Member

    Wow thanks Doug. That's the first anyone has talked about.

    When you say "GPS based" do you mean that you need a gps as well?? If so what model?

    Thanks

    Shawn T
    Wichita KS
     
  4. Saildude
    Joined: Jun 2011
    Posts: 84
    Likes: 9, Points: 0, Legacy Rep: 119
    Location: Seattle, Washington, USA

    Saildude Junior Member

    The GPS should be built into the unit - I have seen a few in catalogs but have not payed much attention to them - works like a handheld GPS unit but they make the display more sailboat friendly and have a mount of some sort.
     
  5. rxcomposite
    Joined: Jan 2005
    Posts: 2,193
    Likes: 281, Points: 83, Legacy Rep: 1110
    Location: Philippines

    rxcomposite Senior Member

    Why not just use a handheld GPS with a remote antenna connection?
     
  6. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    =================
    The unit is complete as is -you need nothing else except batteries and a boat. Comes with a mounting bracket. Has a number of other features including heading and remembers "max" speed.
     
  7. DCockey
    Joined: Oct 2009
    Posts: 4,858
    Likes: 397, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    I've used a handheld GPS in the cockpit of a 20' sailboat without an external antenna with no problems.
     
  8. rxcomposite
    Joined: Jan 2005
    Posts: 2,193
    Likes: 281, Points: 83, Legacy Rep: 1110
    Location: Philippines

    rxcomposite Senior Member

    Won't work with a metal or metal cluttered roof.
     
  9. DCockey
    Joined: Oct 2009
    Posts: 4,858
    Likes: 397, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    The original poster has an 18' fiberglass sailboat. No need for him to add the complication of an external antenna.
     
  10. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 115, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    GPS can not determine your speed thru the water. Sailing yachts and primary navigation require a speed thru the water sensor.

    Install one with a flush thruhull and removable sensor. remove before haul out to prevent damage..
     
  11. DCockey
    Joined: Oct 2009
    Posts: 4,858
    Likes: 397, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    Why would you rather know the speed through the water rather than speed over the bottom for primary navigation purposes?

    Speed through water is what's needed if you are trying to optimize the speed through the water, for example experimenting with sail trim. For most other purposes speed over the bottom is more important, even for sailing yachts. If you are racing then what is important is speed and course relative to the next mark which is generally fixed to the bottom.

    The original poster has a small boat which is trailered. Having to remove a sensor every time the boat is put on the trailer and reinstall it after launching, possibly every time the boat is used, is a nuisance. A different situation than a fifty foot yacht which is hauled once a year or so.
     
  12. mydauphin
    Joined: Apr 2007
    Posts: 2,164
    Likes: 53, Points: 48, Legacy Rep: 575
    Location: Florida

    mydauphin Senior Member

    Why the heck do you care how fast you are going on a 18' boat, just enjoy the ride and don't get out of site of land.
     
  13. Stumble
    Joined: Oct 2008
    Posts: 1,896
    Likes: 71, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    The difference is that a thru-hull requires a hole be drilled into the boat, with the sensor protruding through the hole. A in hull sends a beam through the hull of the boat, they are easier to install , but much less accurate, and tricky to install right.

    You could also go with a transom hung transducer, which just bolts onto the back of the boat. Usually the cheapest, and work ok.


    Personally on a boat this size I would go with a speed puck, or another gps enabled racing compass (like the tack-tick). If I bothered with anything.
     
  14. Jetboy
    Joined: Feb 2012
    Posts: 278
    Likes: 6, Points: 0, Legacy Rep: 65
    Location: USA

    Jetboy Senior Member

    Most smart phones will do all of this AND play music while you're out and about. Plus they can log the map of your trip, calculate vmg to any point, take pictures... etc. If you don't want to use your real phone, but a used smart phone for $150 and a waterproof case and it will do a lot more than the gps puck.

    If you want something handier, I have a gps watch for running and cycling. It has almost all the functionality of a regular handheld GPS in a smaller package. They go for about $175. Plus it's water proof if you accidentally go swimming you can measure your swimming speed too.
     

  15. rxcomposite
    Joined: Jan 2005
    Posts: 2,193
    Likes: 281, Points: 83, Legacy Rep: 1110
    Location: Philippines

    rxcomposite Senior Member

    Yes. I have a Nokia "Navigator" mobile phone. And it talks too giving me directions. I mount it on the dashboard of the car or I take the window seat when on a bus. Works great but you need to subscribe for the service.

    I haven't used it as a speed meter but if it is so smart, it must have a setting. It tells me the route whether by walking or travelling by car. And it corrects itself if I make/miss a turn.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.