[OSM-talk] connection between 2 islands

[Cartinus]

On Tuesday 01 December 2009 06:12:07 John F. Eldredge wrote:
> Just out of curiosity, what is used for the coastline of an oceanic island?
>  High tide mark?  Low tide mark?  The average of the two?

from <http://wiki.openstreetmap.org/wiki/Tag:natural%3Dcoastline>

Tidal position

The coastline way should be positioned at Mean High Water Spring (MHWS), 
the "average high tide" line. And in non-tidal waters (tide less then 30 cm) 
at Mean Sea Level (MSL).

Realistically speaking the vast majority of our natural=coastline ways will be 
based on PGS data for a long time to come, and some will be corrected based 
on Yahoo! Aerial Imagery (variable tide level), but if you get the 
opportunity to fix up the data while out surveying, then the high tide 
position is the one to go for. 



-- 
m.v.g.,
Cartinus