do I really need a log?

[carrswood]

if I wanted to save money when replacing old instruments do I really need to go to the expense of fitting a new log and head unit? Sure its a nice to have but with the marvels of GPS plotters I can see my SOG and read off my track distance too. Am I missing anything? (unless of course the GPS goes down)

If I went for a fishfinder transducer then I could avoid replacing the depth gauge too

Because I used to dinghy race I like to trim the boat nicely so a wind speed and direction gauge are a must.

 

[Aeolus]

I've got rid of mine

Well, so far I've removed the readout unit - have yet to take the boat out to remove the impeller. I've got a chart plotter fitted in the cockpit and find that is much simpler. If the GPS failed, then I wouldn't know exactly how fast I was going - not really a problem as I'm rarely in a hurry.

 

[sailorman]

Well, so far I've removed the readout unit - have yet to take the boat out to remove the impeller. I've got a chart plotter fitted in the cockpit and find that is much simpler. If the GPS failed, then I wouldn't know exactly how fast I was going - not really a problem as I'm rarely in a hurry.

[If the GPS failed, then I wouldn't know exactly how fast I was going - not really a problem as I'm rarely in a hurry.]

Distance "Run" is very usefull

 

[FlyingSpud]

Struck me the other day that I have not put the impeller in all season. The issue is, who navigates in coastal areas now traditionally, hardly anyone I would guess

 

[Aeolus]

Distance run....

....is very useful, especially when navigating offshore. For that I use the chart plotter plus I have a battery powered backup GPS. I know the GPS satellite system may fail or be switched off, or I may be struck by lightening and lose all electro gadgets. However the log failing to work (yet again) due to banacles, gremlins etc. is a much more frequent occurence and I had given up on expecting it to work, hence I've decommissioned it.

When I'm mid-atlantic, after the lightening strike, I'l just have to sling a piece of wood tied to a piece of string and count the knots.

 

[Blue5]

Do I really need a log

....is very useful, especially when navigating offshore. For that I use the chart plotter plus I have a battery powered backup GPS. I know the GPS satellite system may fail or be switched off, or I may be struck by lightening and lose all electro gadgets. However the log failing to work (yet again) due to banacles, gremlins etc. is a much more frequent occurence and I had given up on expecting it to work, hence I've decommissioned it.

When I'm mid-atlantic, after the lightening strike, I'l just have to sling a piece of wood tied to a piece of string and count the knots.

At Gosport I have found I need to take it out at least once a month to clean barnacles etc to keep it working, nice to compare with SOG to work out tide but I suspect the log will eventually go the way of the sextant, the die hards will use it but most will just succumb to GPS/Chartplotter

 

[dukes4monny]

I trail my Wasp log occasionally when I want to find out how much tide I'm battling by comparing it with the SOG..........helps to decide whether the iron sail is to be used.

 

[sarabande]

if you were restricted to just ONE instrument, the log is the key essential. Without knowing how far you have run, you can't know where you are; and if you don't know where you are....

All other instruments, and I mean that, ALL others can be substituted by skills and experience. A log and a chart; no more for the bare essentials.

Go ahead and rely on the complete infallibility of your GPS, so long as your family and the insurance company are happy, too.

Perhaps the mags ought to undertake some research into how many times a GPS has failed, how many times the signal has disappeared, in order to give some weight to the arguments for/against the need for backup kit.

 

[carrswood]

Saarabande - your quite right. The real seamen can work out a lot from distance run esp if the worst happens and you lose your GPS signal. Albeit a rough calculation.

Tell me, assuming your GPS is fully operational - for accuracy is a GPS trip function the true log distance covered? A paddle wheel log tells you the distance run but doesn't take account of the effects of tide and wind - so at the end of your passage it doesn't tell you exactly the true distance covered? (I guess i'm trying to justify to myself why I don't fit a new log)

Just out of interest - is it common to lose a GPS signal for longer than a brief moment and if so - for how long?

 

[jwilson]

Yes, a log is a primary instrument, but they are rarely very accurate, and once you know your boat you can make a fairly good estimation of speed through the water in most conditions.

I sailed a lot of miles without a log back when I could not afford one. A compass is essential, a log is not. The first bit of electronics I bought was a Seafarer echosounder. Of course knowing the depth then led me to cut corners and creep inshore to cheat the tide, so I ran aground more often than before I had it!

I too often do not bother to put the impeller in these days - if I leave it in I find three days moored will often gum it up with mini-shrimps hiding in the paddles.

 

[shmoo]

At Gosport I have found I need to take it out at least once a month

I thought you were supposed to take it out every time you put the boat back on its berth.

You mean all that "one plug out, quick-the-boats-sinking, other plug in" business could have been down to once a month? No one told me!

 

[VicS]

All other instruments, and I mean that, ALL others can be substituted by skills and experience

A compass is pretty useful too. If restricted to only one It'd have to be the compass I think.
I have found my way home in dense fog using the compass and the depth sounder.

 

[planteater]

If I went for a fishfinder transducer then I could avoid replacing the depth gauge too

This occurred to me but the power consumption of a fishfinder is way higher than that of depth sounder. If you sail more than you motor, reside on a swing mooring and have limited battery capacity it is an issue.

 

[Maree]

If restricted to just one instrument, I think I'd choose depth.....

That must be the east coast in me.

 

[noelex]

Because I used to dinghy race I like to trim the boat nicely so a wind speed and direction gauge are a must.

My instruments needed replacing recently and after much thought I replaced the log and depth through hulls with fishfinder and depth. I think the spare depth reading is more important than the STW reading.
Be aware that some instruments (ST60 in particular) will not give true wind from the GPS derived SOG. However my B&G instruments will calculate true wind from GPS derived speed.

 

[sarabande]

VicS

I meant electronic instrument, sorry. I presumed that everyone has a magnetic compass, but on reflection that is likely to be wrong.

BTW, my first log was a rotating spinner type; it's still in a garage somewhere; then I used the Chernikeefe, courtesy of the GFL.

 

[Abestea]

Shove another log on the fire!!!

Instruments are driving me up the wall.

First year - no log, no depth (well old seafarer that did not like the boat moving even with new castor oil), wind instruments worked well!

Second year - log (well only when i put it into reverse to clear the junk out of it), still poor depth situation, thank goodness for wind instrument.

This year - new depth gauge (yay!), log now non existent, wind instruments have stopped working (well unless the wind was gusting 176 knots of Dunoon).

moral - sod it! the depth gauge works and that is all that matters and the windex is functioning.

 

[LONG_KEELER]

I think us sailors are pretty good at estimating speed.

Probably due to the accuracy of GPS. It's fun to estimate speed then check with GPS. I reckon to be within 1/2 knot most of the time.

I also like to estimate the tide when at anchor, then using time/distance with a bit of flotsam to check. Not so good here. Always seem to overestimate speed of tide.

 

[William_H]

Paddle Wheel Log

I have sailed on many friend's boats and only onne has had the log working. It is an old Band G ultrasonic doppler log system. Top of the range in 1989.
I got rid of my paddle wheel log many years ago. That out of sheer frustration at the fouling of the paddle. It was just too much trouble cleaning it then drying out the puddle of water in the bilge.
A log system is relatively cheap to buy but like much instrumentation promises wondrous things but lets you down on actual reliability.
I think if I ever sailed where navigation is really needed I would be happy to rely on GPS. Mostly I don't even take the GPS out sailing.
As for depth. Maybe I am unusual in having a light boat. Getting off after running aground is no problem. So I use ole reliable keel as a depth guage. Or eyeballs. Or simply know where it is shallow.
My 2 bobs worth olewill

 

[David_Jersey]

if I wanted to save money when replacing old instruments do I really need to go to the expense of fitting a new log and head unit?

Good question. I wouldn't remove mine, but I wouldn't install one either.

IMO GPS is good enuf when working (99%), and if not then boat speed & distance can be estimated well enuf with a watch. (and prior knowledge of boat).

But if I was going serious distance I would probably take me Walker trailing log (unused ) as a GPS back up.