Buoy Talk


Several weeks ago I wrote about about the importance of navigational buoys, charts, lighthouses, and other aids to navigation (ATON) to Sailing. Echoing the opinions of many other sailors, I suggested that an acurate and internationally recognized system of navigation buoys would be good for sailing, easy to deploy in SL, and have minimal server impact. Equally important, the yacht clubs and SL Coast Guard could provide the educational resources needed to help sailors learn about the RL and SL systems, and the Sailing Community has the scripting expertise to generate a variety of active displays that would use the nav marker location imformation. 

This discussion is still underway on ORG and in different groups, and there might be several possible solutions that all use common protocols (just like real life!).

Baby Buoys

A number of wonderful SL artisans have an interest in nautical buoys, which might seem a little surprising, since nav buoys don’t blow up and aren’t excite or sexgen compatible… but I guess sailors have strange tastes.

Several new buoy designs recently were introduced that use the  IALA-A and IALA-B conventions for SL navigational markers; I’m pretty excited. It looks like SL sailors are all ending up on the same page. The IALA buoy I want to tell you about I just learned about yesterday from Alan Bereford and Karsten Runningbear from Schiffsratten.

Alan’s the guy that made that silly little kid’s toy… you may have heard of it… the Shelly? If you haven’t, don’t worry; nearly every Olympic sailor in recent history knows about the RL version of that boat; ask one of them. Then come back to SL and sail a Shelly. 
IALA-standard menu-driven buoy by Runnigbear and Beresford

IALA-standard menu-driven buoy by Runnigbear and Beresford

 Alan and Karsten have now taken on “the buoy issue” (grin). I’ll give you the highlights of the features that make me so excited:

1. As I said, its IALA-A and -B compatible, so sailors RL and SL will have the same standards.
2. It’s menu-driven, so it takes minimal instruction to use and adjust them;
3. It has multiple modifiable features. Buoys are used for many purposes and in many contexts. It’s mildly frustrating that several very expensive buoys are not user-modifiable. For those prices, they should be user-friendly.
4. It has the standard options of a flashing light or a horn (or both). It has one BIG non-standard option: It can be PHYSICAL. If you bang into it… it moves aside, just like RL.
5. The version I tested also has an menu-optional shout call when the buoy gets hit. It’s obvious, many more script options are on the way.
What can I say? I love it.

Since this was just Beta I, let me leave it there for the moment… I’ll save the pyrotechnics for the finished product! (…did I mention the buoy listens to Mothgirl’s WWC and moves with current and wind? (sorry… grin)).

Rocky Road.

Navigation is, however, far more than just ‘Where the buoys are.”
A critical feature of virtually every type of of nautical chart made in the last dozen centuries is “water depth.”
Is there enough water? Is that course safe in this boat?
If you look at the small section I cut out of a New York nautical chart in the image above, you’ll see the open water is peppered with numbers… they’re all sonar depth records.
How much water a passageway offers your boat is pretty critical.
In SL however, depth is often an interesting, but frequently frustrating problem for sailors. It’s true that the large majority of recent sailboats are equipped with indicators for water depth, so a skipper usually knows how close she can get to the shore. However, for reasons I don’t fully understand, it’s actually much more difficult to get topographic information about the SL grid to use in a chart array for mapping. As far as I can tell, the standard nautical charts one uses in real life to plan a cruise or plot a race course just aren’t available in SL.
 I won’t belabor this point, since I have already discussed it at length recently, but I did want to mention a couple follow-up things…
 I got this bright idea last week for finding and delimiting the ‘shallow spots’ in Blake (grin)… (but please don’t try this at home.)
Atlantic Sea floor
Atlantic Sea floor

Here’s what I did:

First,  I got rid of all that silly water by typing CTRL-ALT-SHFT-7.
Then I took a huge 256x256x1m  phantom mega-prim and sank it to the minimum safe water depth for a J-Class (4.0m, z=15.5 for a 1.0m think platform).
All the seafloor terrain details higher than keel depth show through.  Within a few seconds  you have a photographic record of  the location and the  extent of all submerged hazards in the sim.

 If you look at the picture below, you’ll see in Atlantic Sim  just south of NYC there are two clusters of rocks/ ledges.   On the East side there is a cluster of rocks indicated by the right yellow arrow, just in front of Francois Jacques’ house.  It’s fairly close to land, and you might think it’s out of the way and not a problem.  However, any boat with apparent wind using the Madaket race line enters Atlantic on a beat, usually at a 60° real angle. When I do that in a J-Class I frequently hit those rocks full throttle. 

Let me emphasize again that I’m not really complaining about this… dealing with depth is part of sailing. I am, however, complaining I didn’t know the seafloor elevations!

Phantom megaprim 4m below water shows rocks in Atlantic Sim
Phantom megaprim 4m below water shows rocks in Atlantic Sim

The second group of Atlantic rocks  we need to fix, however. If you look at the picture above, there are rocks located in Atlantic just south of the NYC channel. Any large boat with a deep keel runs a risk of hitting those rocks.  Far worse– two of the rocks are actually inside the racing two-boat zone for the blue-white marker.  We should either remove the rocks or remove the buoy. 

This problem really isn’t anything new. I talked about the “Blake bumps” problem a couple of weeks ago here. Here’s what’s new, however:   

Cynthia Centaur saw me playing with megaprims… and took pity on me ( God bless Cyn).    She then scripted and tested a quite nifty utility that does exactly what I think is needed. The image on the left below shows Nantucket Yacht Club sim; it’s an aerial photograph. The Map picture is even more two dimentsional. The right side of the illustration, however, is a color-correlated plot of the Z-axis elevations in NYC sim, from 0-20m (>=20m is shown as same color, yellow).

Topography of Nantucket Yacht Club Sim

Topography of Nantucket Yacht Club Sim

 Woot!  The next illustration shows Atlantic sim. The left image shows the color gradation for various elevations, and the right image shows color only for spots shallower than 4 meters. At the top of the right image you see two such ‘shallow submerged hazards’ in yellow-orange, one on the left and one of the right (West and East). Those regions on Cyn’s plot are the same submerged rocks I pictured above.

Atlantic seafloor topography. Right image selectively shows z> 16m

Atlantic seafloor topography. Right image selectively shows z> 16m

I’ll leave it up to Cynthia to explain the details of the topographic charting, but it’s my understanding we should be able to map all of Blake Sea  and then come back regularly for updates. Similar to RL charting systems, it’s also possible to superimpose multiple layers that identify coastal features and buoy locations. 

I know maping the floor of blake sea isn’t quite the same as solving the Darfur problem or curing malaria, but in its own way, I thought this was pretty OK.

Keeping a List.

I think most SL and RL sailors would quickly agreed that charts are only as good as the information they contain.  Locations of ban lines and even the shapes of land masses frequently change in SL, so both  chart construction and collection of landmarks for buoys and rez areas is a fairly constant process.  Much of the time a successful sail depends on simple basics such as: Where can I rez my boat?  or  How do I get around ban lines in that marina? 

 Many sailors from different groups, including the Coast Guard and the various yacht clubs have gotten together to collect this kind of information and post it in different places in SL and on the web.  I’m trying to gather much of this information together and organize it into a series of pages of links and maps that highlight current features of   interest to sailors.

The pages will be organized  under the heading SL Aids to Navigation and will probably be broken down by region and feature, Including Landmarks for navigation and race buoys, Locations of lighthouses and Fixed aids to navigation, places to rez boats, and friendy destination marinas and yacht clubs.

If you have such lists, please post them as comments on that page of give them to me as a notecard. I’ll them fit them in to the ongoing information lists for sailors.



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