Orca attack

dunedin

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All the usual suspects in here complain that nobody is doing anything about the Orca attacks.
Then the same suspects complain about the work being done by a body which has made the effort to capture and analyse real data.
They are doing more than the complainers are
PS. I suspect that the CA do know the characteristics of the boats who reported safe passages as well as the reported incidents. And that correlation is not proof of causation. But at least some observed and measured facts is a better start than web grumbling.
 

oldharry

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Correlation is not causation.
Read the report. They are specifically not attributing attacks to the presence of black antifouling. However they ask why a significant number of attacks have occurred against boats that are painted black: "“If, on trouble-free voyages, you’ve only got 25 per cent of boats with black antifouling, why on the attack side, have you got more than 50 per cent with black?”

"...black antifoul is a ‘possible’ concern, and until more data is collected, it can only remain that" he concludes, simply highlighting a curious anomaly in the statistics which may or may not prove to be relevant.
 

DJE

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Trouble is it's a fairly small data set so random variations might be significant. If you go looking for any possible correlation you're likely to come up with something. If there were correlations between attacks and age of boat, number of crew, or some other variable we would probably ignore them.

Really need to see if it's repeated in next year's data.
 

shan

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Read the report. They are specifically not attributing attacks to the presence of black antifouling. However they ask why a significant number of attacks have occurred against boats that are painted black: "“If, on trouble-free voyages, you’ve only got 25 per cent of boats with black antifouling, why on the attack side, have you got more than 50 per cent with black?”

"...black antifoul is a ‘possible’ concern, and until more data is collected, it can only remain that" he concludes, simply highlighting a curious anomaly in the statistics which may or may not prove to be relevant.
The sample size is far too small to draw any such conclusions.
 

Blueboatman

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Oh dear!

In the good old days of Practical Boat Owner someone would have written an article describing how to make your own depth charges. 😁
Or conduct a survey - 1,2 or 3 rudders best ?

Or how to best trail a taserlog ??

Or indeed whether a smearing of whale oil grease on the rudder makes you a friend of the whales ..
 
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