jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,890
Perhaps a poet and don't know it.. I have trouble with meter and rhyme... some of the time...
What the heck is: Loran 797
- Thread starter Fidgit
- Start date
Interesting that Loran used shore based towers, and enhanced GPS I believe now uses shore based towers to provide pin point accuracy. On the commercial vessel I worked on, our client would set up a transmitter on the roof of a hotel and calibrate that to the GPS to give our position within inches.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,890
For clarity sake,
GPS is a satellite system. A GPS navigation device, GPS receiver, or simply GPS is a device that is capable of receiving information from GPS satellites and then to calculate the device's geographical position. Using suitable software, the device may display the position on a map, and it may offer directions. We use on boats hardware and software to display this information on Multi Functional Displays (i.e. chart plotters)
Enhanced GPS (or E-GPS, EGPS, trademarked as eGPS) is a technology designed for mobile phones on GSM and W-CDMA networks, to augment GPS signals to deliver faster location fixes, lower cost implementations and reduced power and processing requirements.
Thanks. I just assumed it is similar to the system we used for underwater surveying. I'm still not clear on how the enhanced GPS system works, but that's OK. I'm an old timer just happy that my chart plotter shows me were I am.
That was LORAN A. Used it from the Mexican border to Kodiac Island, Ak on the commercial fishing boats (salmon, crab, etc.) when I was a teen.
I had one on my first big boat in 1970 on my crossing to Hawaii (that was about as far out as it would reliably work) and it was pretty neat, as every other voyage to Hawaii before that we had to do celestial.
Perhaps a poet and don't know it.. I have trouble with meter and rhyme... some of the time...
The cell towers are fixed and can use the tower signal to improve your location calculation.
I remember using Loran A flying for the Air Force. On the oscilloscope, we would manually move the master and slave signals until they were superimposed. The oscilloscope would provide the time difference that the signals were received. These time lines were printed on the navigators chart. So, much like celestial navigation, this would give us one line of position. Loran A's range for ground waves was about 100-200 miles, but at night the signal would bounce off the ionosphere and could be used in excess of a thousand miles.
Exactly what ours was on the transport We flew a full time navigator on the plane aircraft
I like hanked on jibs. I like having a suit of head sails to choose from.
I know it is considered by most to be a crappy boat but I used to own a MacGregor 22 that had four different headsails and a main with two sets of reef points. I could balance that rig in everything from a 3 kts puff to 35 kts howler. I remember one epic sail when I was flying two handkerchiefs and I invited three teens for rail meat. I was making 6-7 kts in a 35 and we just sliced through the chop... spray over the bow ... wonderful. I can't do that with my roller furled headsail.
I think if I were ever to commission a cruiser... I'd have a roller furled Geneker way out on the sprit for those lighter air days and a solent stay set up aft of the forestay that I could hank a selection of heavier-wind head sails. I imagine that being the ideal set up. I also imagine that I'd really like a gaff main but maybe that is just the romantic in me.
My first big boat came with 23 bags of sails. Everything from storm jibs to gargantuan light air spinnakers. And one of my favorite things to do was change headsails on the foredeck in 40+ knots of wind; NOT!I like hanked on jibs. I like having a suit of head sails to choose from.
I think if I were ever to commission a cruiser... I'd have a roller furled Geneker way out on the sprit for those lighter air days and a solent stay set up aft of the forestay that I could hank a selection of heavier-wind head sails. I imagine that being the ideal set up. I also imagine that I'd really like a gaff main but maybe that is just the romantic in me.
If you plan to cruise the Caribbean, you'll be sailing with a deeply reefed main and a Yankee Jib or a partially rolled up genoa, most of the time.
But when Christmas Winds or the heavy trades set in, you will be sitting at anchor (or on a mooring or in a slip) until the winds abate, if you don't have roller furling headsails at the minimum. You have lees behind the islands with extremely light and fluky winds with possibly 40+ knot gusts coming down the valleys, so a drifter /Geneker isn't the right sail. As you come out from the lee, with a furling sail you can take in as much sail as you need to, without a trip up to the foredeck to change headsails, never mind the necessary open hatch forward taking blue water as you move the sails in and out of the boat.
Of course, you could always drop your channel crossing sails and motor the lees, instead of all that work.
Very few cruising boats today use hanked sails and there's a pretty good reason why. If you choose not to, then that is your choice, but I doubt you'll be doing half the sailing as those with infinite reefing at the pull of a string.
You have a lot more experience that I do. All of my cruising has been coastal to VA and NC or in a lake. I've owned 7 sailboats in the past 18 years and only the last two had roller furled headsails. I have not liked the sail shape on either once I start to furl. I remind myself they are not called roller reefers but furlers. What I have found on my Hunter is that she will sail very well with headsail only. So my first reef is to the main, the second is to take the main all the way down, the third is to roll in about 25% of the head sail and if it is still too much, I pack it in and motor. I can keep my H26 comfortable to about 25 mph and then I give up. .... The only solid point to connect a solent stay would be the U-bolt in the anchor locker but I'd have to leave the locker open or drill a hole in the hatch... (hmmm...that actually might work... ????) It would be really nice if I could quickly deploy a small heavy jib. I think a second set of reef points in the main would also be nice. If I could keep my boat on her feet in the 30 mph range, I'd call it a win.
I've never had a jib hat roller furled. Always hank on sails. My current jib has reef points, just like the main sai. I is a working jib size, and reefs to storm jib. Never needed
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,890
There have been improvements not necessarily solutions to the shape of furler reefing. By placing “padding” in the luff the sail can be more tightly wound around the furler extrusion. With the extrusion design changes a more aerodynamic shape can be made. And just because there are furlers and sails on them does not mean you can not change the sail to adapt to changing conditions. I have a 90% jib that I set when the conditions dictate or if I am concerned while sailing solo that the Breeze is changing and the smaller sail would be a better fit. Sure a hank on has it’s benefits but a couple of sizes of sails set for your furler can give you multiple sail options.
John, I think that is AGPS (Augmented) not EGPS. Operative words being "I think".
And... did this thread just turn from Loran to hanked on jib?
Don't forget your phone. On a pasage from Rockport Texas to isla Mujeres, we discovered the ships GPS had no chip for the north coast of Yucatan, when we tore a sail and needed to find a shore spot- not enough fuel to make Isla. So, using INavx on the phone we navigated from 100 miles offshore to between the jetties at Progreso Yucatan, where we had the sail repaired. This was a roller furler on a 41 footer.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,890
It appears to be drift...
I looked up the “Augmented” GPS and found this..https://en.wikipedia.org/wiki/GNSS_augmentation
It reads different than the “Enhanced” GPS. Sounds more based on satellite signal timing changes than the Cell Tower based model for the cell phone systems used by Apple and others.
I looked up the “Augmented” GPS and found this..https://en.wikipedia.org/wiki/GNSS_augmentation
It reads different than the “Enhanced” GPS. Sounds more based on satellite signal timing changes than the Cell Tower based model for the cell phone systems used by Apple and others.
You don't often cross from the states to the Caribbean and sail down there, do you? lol