On Thu, 08 Jul 2010 09:35:12 -0700, John Navas
wrote:

There is a long and noble tradition of crowd-sourced surveys here. I
have a set of Clyde Cruising Club sketch charts which were put
together over decades from the contributions of hundreds of yachtsmen.
They remain by far the most detailed information available in many
places.

Otherwise known as Russian Roulette. No thanks.

It is easy to take the position that *all* charting should be done to
state-of-the-art, professional standards. There are many parts of
the world where that is not going to happen however, certainly not in
our life time, probably not ever.

What is your solution for cruising those areas?

1. My own navigation and instruments.
2. Entering with good mid-day light.
3. Following well-crewed boats with more draft.
4. Aerial photos.
With a grain of salt:
5. Cruising guides with a well-established track record.
6. Local knowledge from people I know and trust.
7. Local knowledge from other sources under advisement.

No one could argue with 1 and 2 but some would take issue with #3, a
last resort at best for me. Aerial photos of the Google Earth variety
have potential in some areas with good resolution if we could figure
out how to download the imagery and index it by lat/lon.

Items 5, 6 and 7 seem like a contradiction since they are often a form
of "crowd sourced" data that you claim to distrust, particularly the
caveat about a well-established track record. Track records are most
certainly a form of group opinion and feedback.