{"id":2267,"date":"2008-07-05T00:00:00","date_gmt":"2008-07-05T00:00:00","guid":{"rendered":"https:\/\/setsail.com\/?p=2267"},"modified":"2009-04-15T08:51:51","modified_gmt":"2009-04-15T13:51:51","slug":"s_logs-dashew-dashew519","status":"publish","type":"post","link":"https:\/\/setsail.com\/s_logs-dashew-dashew519\/","title":{"rendered":"Practicing with Icebergs"},"content":{"rendered":"
Iceberg School: Practicing seamanship tactics, and comparing what the sonar shows vs. the human eye. Great iceberg photos from a rare sunny day!<\/div>\n

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These big bergs are fascinating. However, they also bring a healthy does of risk into the cruising equation.<\/p>\n

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The big guys are easy to see and spot on radar, but the smaller pieces, like these bergy bits, are much harder to pick out. These do not show up on radar (unless it is flat calm) and they hide amongst white caps in anything over 17 knots of wind.<\/p>\n

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So, we have been testing our radar and sonar as well as our own eyes. The photo above is looking at a berg which is about 1200 feet (360m) off our starboard beam.<\/p>\n

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The radar (left) is set to its shortest range, so each range ring represents 300 feet (90m) (we are seeing the bigger bergs at six to ten miles depending on their shape and size). The sonar on the right is seeing an underwater ledge extending in our direction at a distance of about 600 feet (180m).<\/p>\n

\"melting<\/div>\n<\/p>\n

Temperatures have been pleasant the last few days, and you can see the result on the iceberg surface.<\/p>\n

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We are not the only one checking out this bit of Greenland ice. When the humpback whale moved off we followed, in case he sensed something we had missed.<\/p>\n

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Our favorite iceberg so far. Between the shape, blue sky, and clouds, you could not ask for more.<\/p>\n

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Looks like this guy recently lost a piece of his body.<\/p>\n

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Back to school. Looking from the inside out off the port beam now.<\/p>\n

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The underwater section of the iceberg is about 570 feet ( 169m) away. The Furuno CH270 sonar is in horizontal viewing mode.<\/p>\n

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And then a look at the underwater shape in vertical mode. Note the "shelf" which appears to be extending off the base. We are not sure if this is the ocean bottom, as it is the right depth for the sea floor, or a section of berg. Whichever, the underwater sections do appear to extend well beyond the visual above-water perimeter, so we are going to give these guys a lot more clearance in the future.<\/p>\n","protected":false},"excerpt":{"rendered":"

Iceberg School: Practicing seamanship tactics, and comparing what the sonar shows vs. the human eye. Great iceberg photos from a …Read More<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-2267","post","type-post","status-publish","format-standard","hentry","category-dashew-blog"],"_links":{"self":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/2267"}],"collection":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/comments?post=2267"}],"version-history":[{"count":0,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/2267\/revisions"}],"wp:attachment":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/media?parent=2267"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/categories?post=2267"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/tags?post=2267"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}