Small boat radar

[pmagowan]

All fairly familiar.
I think it's a big ask to man a boat effectively in fog singlehanded. I don't sail singlehanded very much at all.
If I did I think I'd be serious about autopilots.
Autopilot is a big plus in fog anyway, many good helms are all over the shop in fog.
In fact I suspect most of us take a while to get 'dialled in' to steering a good course in bad vis without much wind input, if it's the first time we've had to do it this season?
It's a lot harder than racing upwind to the tell-tales IMHO.

None of the boats I sail are primarily set up for singlehanded or even 'bloke plus SWMBO who is not that involved' if you see what I mean.
I think that influences where you want the radar among other things.

Without reference points a human can not steer a straight course. we are pre-programmed to steer a course of ever decreasing circles. Strange sensations occur in fog where you start to doubt your equipment as it tells you that your 'straight course' is anything but. Radar adds another point of reference which helps to convince you that your instruments are, in fact, correct.

 

[ghostlymoron]

Essential = absolutely necessary; indispensable:

 

[GrahamM376]

All fairly familiar.
I think it's a big ask to man a boat effectively in fog singlehanded. I don't sail singlehanded very much at all.
If I did I think I'd be serious about autopilots.
Autopilot is a big plus in fog anyway, many good helms are all over the shop in fog.
In fact I suspect most of us take a while to get 'dialled in' to steering a good course in bad vis without much wind input, if it's the first time we've had to do it this season?
It's a lot harder than racing upwind to the tell-tales IMHO.

None of the boats I sail are primarily set up for singlehanded or even 'bloke plus SWMBO who is not that involved' if you see what I mean.
I think that influences where you want the radar among other things.

Agree with just about everything you say, it's very easy to get disorientated in fog, particularly when no wind. We were in the inshore traffic zone a couple of weeks ago about to pass Tarifa (Gib Straits) when thick fog descended and there were just too many close targets around to leave on autopilot so had to hand steer and rely on the good old fashioned compass as lag on gps course makes it too slow for accuracy. Although in those circumstances I can see the radar from the helm, SWMBO is the main operator, adjusting range, ebl, etc as necessary. When things less fraught, we can both operate sitting under the sprayhood and use the autopilot remote for course changes.

 

[GrahamM376]

Without reference points a human can not steer a straight course. we are pre-programmed to steer a course of ever decreasing circles. Strange sensations occur in fog where you start to doubt your equipment as it tells you that your 'straight course' is anything but. Radar adds another point of reference which helps to convince you that your instruments are, in fact, correct.

It's a bit like (but not as bad as) blind flying with a limited panel, once you start chasing the ASI, you're in trouble.

 

[pmagowan]

It's a bit like (but not as bad as) blind flying with a limited panel, once you start chasing the ASI, you're in trouble.

Yes, I have heard of accidents in flying caused by similar dissorientations. The human brain uses various senses to determine what way up you are and which way you are heading. It likes to check these against each other and it can get quite confused if their is a conflict or if it is not getting information form one 'sensor'. This is what causes seasickness. Your inner ear is rightly detecting the movement whereas your eyes are often detecting no relative movement with the ship. The brain doesn't know which to believe and so starts going through an 'emergency protocol' for possible causes. Being that we are not naturally at home on the sea and the brain is designed for solid ground it does not immediately suspect that the ground is moving. Instead it thinks it has been poisoned and so activates the 'evacuate poisoned food' system.

The brain is not a very reliable processor and people should be aware of its flaws and be ready to disregard sensations that do not fit with well calibrated and duplicated sensors.

 

[JumbleDuck]

Semantics I'm afraid but its not ESSENTIAL or every boat would have one. Agree it would be useful but I haven't got one.

I think a reliable battery system is more important than a reliable battery monitor. In fact if you have the former you don't need the latter. Remember when cars had oil pressure gauges?

 

[maxi77]

Without reference points a human can not steer a straight course. we are pre-programmed to steer a course of ever decreasing circles. Strange sensations occur in fog where you start to doubt your equipment as it tells you that your 'straight course' is anything but. Radar adds another point of reference which helps to convince you that your instruments are, in fact, correct.

Then how do submariners mansge then withno externalpoints of reference just a compass/heading display. Bligh covered many miles of reference free ocean in a small boat with a compass. Do modern yachts not carry a compass?

 

[pmagowan]

A compass is an artificial point of reference. A submariner has no choice but to ignore their own senses and use artificial means. I think you missed my point.

 

[lw395]

Then how do submariners mansge then withno externalpoints of reference just a compass/heading display. Bligh covered many miles of reference free ocean in a small boat with a compass. Do modern yachts not carry a compass?

I expect Bligh, like most people, steered from moment to moment using the sun or stars as a short term reference.
But he was only worried about his average course and making progress. Whereas in fog, you want to steer a steady course so others can track you on theirr radar, and your heading-up radar plot makes sense.
Weaving +/- 10 degrees does not affect progress much, but it makes plotting radar contacts very much harder.

I don't know that much about subs.
Do they hand steer very much?
Being below the waves and all that, maybe they naturally track straighter than my little boat bobbing about in the Channel?
And of course they are driven by full time people who will have practised a fair bit (and only occasionally hit Scotland!).