Radar in 2020

[laika]

I think we can all acknowledge that boating is a many faceted passtime and not only do our types of sailing differ but what we consider core to our enjoyment does too so I don't think there's a definitive list of "essentials".

I could sail a boat without a depth sounder but it would be restrictive. I've followed contour lines in fog. I sometimes use contour lines in combination with bearings to define waypoints in my passage plans. Per Jimi's comment above depth tells me when I need to tack. Silt can shift around and accumulate between dredging so when entering an anchorage I'm usually armed with my "how much will the tide fall from now?" calculation and take a spin round looking at the depth before choosing where to drop. I recognise others may trust the chart and and GPS and their own pressure adjustment and look for a spot with enough water at low water but personally I'd want to add a hefty margin of error if doing that. Same thing applies to mooring buoys in marginal parts of rivers or inlets. Without a sounder to confirm that the depth I've calculated for now matches what the sounder tells me have nothing to reassure me that my calculation that I should still have water under the keep at low tide is correct. I like being reassured that my calculation of current tidal height matches the chart before I head over the green bit I think I should be fine to cross.

Of course a lead line would work for some of those cases: not so much short tacking up a river perhaps

EDIT: For clarification, I recognise that my non-reliance on GPS and non-use GPS waypoints in passage plans is an affectation akin to folks who eschew CDs in favour of vinyl. This is not because I'm clinging to the the way I've always done it (I came late to sailing and am a reasonable way off retirement age) but just because (ref: para 1) I enjoy "analogue" navigation. Contour lines aside, my other reasons for liking the sounder stand. Doubly so since my boat is in Brighton.

 

[Uricanejack]

Probably my age.
I am an analogue guy for most of life’s activities. Sometimes I wander into the digital age for convenience.
Then back to my analog ways.
I don’t use waypoints as a starting point. The way points are converted from positions derived from a number of different sources.

The point being the waypoints I do use. match what I use for visual, radar, and in at least one important occasion depth conture.

from a personal perspective. I find it much easier to use traditional methods with a pencil when figuring out a new route

 

[TernVI]

My point really was that the vast majority of boaters in the solent don't pilot into narrow channels, they drive from Southampton or Hamble to Cowes or Yarmouth and stick to the channels when doing so. As such, a plotter is useful to see where the channels and shallow bits are but the depth sounder is only useful if you venture onto those shallow parts.
For what it's worth I started this thread to discuss what's needed rather than how it's currently done as I find it interesting to see whether the way it's done is time for a change. Depth sounders were certainly useful when reliable charts and location were less easy to come by but I think less so as charts become ever more accurate and gps can tell you where the front and back of your boat are. Yes, there might be something new on the bottom, but there are almost no circumstances where a depth sounder will prevent that collision if you think about it.

Really?
The plotter will tell me what the chart thinks the depth should be, where I am give or take a few metres lat and long.
The sounder tells me exactly what's under the boat.
If I'm near the edge of the channel, it's very useful.
If the tide is higher/lower than predicted it's very useful.

GPS is not 100%.
When things get difficult, at the very least it's nice to have an independent confirmation from the depth.

 

[st599]

Not sure the large racing crews avoid the shallows. Unless you mean proper shallows like less than 20cm under the keel.

 

[LadyInBed]

If I could afford to buy and maintain a boat around 40ft then I should be able to afford to buy a RADAR.
When I bought my 33 footer twenty years ago it came with only basic instrumentation so I budgeted for CP, RADAR, AH and WG then later AIS Rx and solar. They all still work well so I will only upgrade when the current instrument fails, except the AIS, which I upgraded to a Transceiver as it is such a useful tool and affordable.
As my RADAR only gets used infrequently I can't justify an upgrade as much as I would like a new digital one.
The amount of instrumentation and equipment you need depends on the type of sailing you do, if you race then sails are probably a more important item. I try to get away for weeks / months at a time so the electronics and anchor are more important.

 

[jimi]

I suppose if you stick to battleship courses you don’t need a depthsounder but ais and radar to avoid battleships might be helpful

 

[dune16]

Because I like gadgets I did spec my Dufour 430 with the new Raymarine Quantum 2. Now I know it's unlikely I'll need it much in the med but it's nice to know it's there if I ever really needed it. I've played around with it and in overlay mode at night it did make sense, I certainly don't feel like I need to go on a course to get a basic understanding of a modern system.

 

[westhinder]

I suppose if you stick to battleship courses you don’t need a depthsounder but ais and radar to avoid battleships might be helpful

In that case radar in particular as battleships do often switch off AIS and the chance that even an inexperienced operator will not notice a battleship on his display is slight, except of course if it is one of those newfangled stealth battleships. ?

 

[prv]

IMHO the depthsounder is one of THE essential bits of kit on a boat!

Same. For coastal sailing I'd consider it the most essential piece of electronics on board. I also think it's no coincidence that it was the first to be widely adopted.

Everything else that instruments tell you, you can also detect (perhaps less accurately) with your eyes and other senses. You can see how fast the water is going past, you can feel the wind and see its effects, in coastal pilotage you can see where you are by landmarks and buoyage. But in typical greenish UK water, you cannot see how close you are to hitting the bottom. The sounder is the only practical way to tell.

Pete

 

[prv]

My point really was that the vast majority of boaters in the solent don't pilot into narrow channels, they drive from Southampton or Hamble to Cowes or Yarmouth and stick to the channels when doing so.

That doesn't match my observations at all. Yachts don't follow the buoyed shipping channels down Southampton Water or the Solent, they are spread out more or less evenly across the navigable area of water. Indeed you will normally see more yachts cutting across the shallows to the southwest of Calshot Spit than you will in the Thorn Channel adjacent to them.

Using the full width of the water when beating, tacking when the sounder drops below some figure you've decided you're comfortable with, is a very normal way of getting around. Do you really tack back and forth only between the buoys?

(Motorboats are more inclined to follow channels, because at their speed they have less need to take the shortest route, a sounder may not give enough warning, and of course they never need to tack.)

Pete

 

[lustyd]

To be fair those shallows are deep enough for small boats, and are marked as such on the chart. How many of those yachts do you think are actively watching the depth guage? When I said channels take that to mean the bits of the chart showing a depth of water. There are no places in the solent I'm aware of that you'd hit the bottom if following your plotter rather than your depth guage.

 

[prv]

To be fair those shallows are deep enough for small boats, and are marked as such on the chart. How many of those yachts do you think are actively watching the depth guage?

I'd expect most of them. And I wouldn't assume that all those which aren't, are glued to a zoomed-in plotter instead.

There are no places in the solent I'm aware of that you'd hit the bottom if following your plotter rather than your depth guage.

Certainly I'm not going to claim that there are gross inaccuracies in the chart data in the central Solent, nor GPS anomalies that present a more than theoretical risk. It just seems far easier and more convenient to keep clear of the bottom by... measuring where the bottom actually is and displaying that as a large number at the front of the cockpit.

To do the same thing with a typical plotter, you'd have to be so zoomed in as to be more or less useless for monitoring where you're going, and you'd have to constantly be keeping track of the amount of tide to add to the charted soundings. No, it's not difficult maths, but still, compared to "keep big number above companionway larger than 2"...?

Pete

 

[lustyd]

You're not going to keep clear of the bottom in front of you by measuring the bottom below you either. This only really helps when you know you're approaching shallow ground on purpose. In cases where there are honking great big rocks plotters are considerably more useful - the Scillies is a great example of where a depth guage is useless because by the time it beeps you've hit the rock.

I'm not suggesting people stop fitting them, but I do find it fascinating the things people say to justify the status quo.

 

[LadyInBed]

For coastal sailing I'd consider it the most essential piece of electronics on board.

In truth, I seldom turn my echo sounder on! If I have it on going up and down the Wareham channel it quite often gets down to 0.1m and starts flashing, even when I'm in the middle of the channel, so I don't bother with it, I'm either afloat or plowing mud (bilge keel draws 1.4m).
Tacking into shore, when I get to the 5m mark on the CP I tack, that's normally close enough for me.

 

[prv]

You're not going to keep clear of the bottom in front of you by measuring the bottom below you either.

I am, and have done for twenty years, because where I sail the bottom below me is a very good guide to where the bottom in front of me is about to be. There are very few exceptions (Ryde Sands, the Shingles...) and they're well-known for precisely that reason.

In cases where there are honking great big rocks plotters are considerably more useful

This is entirely true, and something I meant to add to my previous post but forgot. Yes, in rocky areas (my example would be the Channel Islands) the plotter is what matters (or the transit marks...). When I sail there I operate in a rather different style to in and around the Solent. But I also don't cut things as fine, precisely because I can't directly measure my clearance from underwater obstructions.

Also, even in the Channel Islands, we did very nearly come a cropper by following the chart instead of the real world. We anchored in the basin by Maitresse Ile in the Minkies, arriving from the south, and then tried to leave through the easier-looking northern channel. We had the latest available updates on both plotter and paper chart, and should have had plenty of depth, but in fact an uncharted sandbar had grown across it. Even now, checking Navionics four years later, the chart says somewhere between 2 and 5 metres (no actual sounding, though, just contours...) but there's a user-contributed note from 2018 saying it dries 2-3m. We had to feel our way out on the sounder on a fast-falling tide and frankly only just made it - in retrospect it would have been far more prudent to have returned to the safety of the basin and waited six hours for more water.

Pete

 

[Robin]

I am, and have done for twenty years, because where I sail the bottom below me is a very good guide to where the bottom in front of me is about to be. There are very few exceptions (Ryde Sands, the Shingles...) and they're well-known for precisely that reason.



This is entirely true, and something I meant to add to my previous post but forgot. Yes, in rocky areas (my example would be the Channel Islands) the plotter is what matters (or the transit marks...). When I sail there I operate in a rather different style to in and around the Solent. But I also don't cut things as fine, precisely because I can't directly measure my clearance from underwater obstructions.

Also, even in the Channel Islands, we did very nearly come a cropper by following the chart instead of the real world. We anchored in the basin by Maitresse Ile in the Minkies, arriving from the south, and then tried to leave through the easier-looking northern channel. We had the latest available updates on both plotter and paper chart, and should have had plenty of depth, but in fact an uncharted sandbar had grown across it. Even now, checking Navionics four years later, the chart says somewhere between 2 and 5 metres (no actual sounding, though, just contours...) but there's a user-contributed note from 2018 saying it dries 2-3m. We had to feel our way out on the sounder on a fast-falling tide and frankly only just made it - in retrospect it would have been far more prudent to have returned to the safety of the basin and waited six hours for more water.

Pete

Probably over 15years ago now but we had a similar experience when going out of that same spot, distinctly puckering as I recall with a 2.1 metre draught and depth alarm going berserk along with 'er indoors. Our plotter then was running on C-Map.

 

[st599]

To be fair those shallows are deep enough for small boats, and are marked as such on the chart. How many of those yachts do you think are actively watching the depth guage? When I said channels take that to mean the bits of the chart showing a depth of water. There are no places in the solent I'm aware of that you'd hit the bottom if following your plotter rather than your depth guage.

Bottom of Springs, High Pressure, I've ran aground in the middle of the North Channel. The Skipper was most amused, although he did agree that there *should* have been plenty of water there. But there wasn't.

 

[michael_w]

Radar like an echo sounder is utterly up to date. No delay at all!

 

[st599]

Radar like an echo sounder is utterly up to date. No delay at all!

Depends on which function you're using. MARPA has a delay, Wake has a delay. On the more modern FMCW any Doppler calculation will have a delay (albeit small).

 

[TernVI]

Radar like an echo sounder is utterly up to date. No delay at all!

There's often a long processing delay in the meatware.