[PUP] Safety & Exploration

[Mike Maurice]

The world beyond the well surveyed is a world of real risks. The 
coastline of the US is well surveyed. The US West coast is amazingly 
well surveyed. The background of this well surveyed coastline is a story 
in itself.

If you want to read about this, see "Waves and Beaches" by Willard 
Bascom. The survey work was begun in WWII and was part in parcel with an 
effort to provide the defensive mapping and charting needed in case of 
an attack, most likely by the Japanese. This survey work was carried on 
during the winter months and in Washington and Oregon, sometimes in 
rough weather and in conditions which today seem more suicidal than 
practical.

Based on my own on-site examinations and comparing the present charts to 
the actual sites the level of detail is simply awesome. For instance the 
number of rocks constituting a hazard, in water less than 30 feet of 
depth along the entire outer coast that are not charted, I would guess 
numbers less than 10, total. Since, I can not name even one, the total 
may be less than 10. I have explored many of the little used anchorages 
along the coast and have never found anything contrary to the charts.

However, once you leave the US the situation changes dramatically. 
Exploring coves in Canada, Alaska and beyond is risky business. If we 
have a major earthquake along the US West coast, there could be serious 
uplifting which would change the risks substantially. In Prince William 
Sound in Alaska after the 1964 quake, the uplift was on the order of 30 
feet in some places.

Because of this I am inclined to think that long range cruisers should 
have at least 2 depth finders; one forward and one aft. I would make one 
of them a graphical display type and if it had a range of at least 3000 
feet it would be useful for spotting low lying atolls before riding up 
over them. They tend to rise out of deep water with little warning. The 
3000 foot curve may be only 1/4 mile from the exposed reef.

Twin screw boats have a major advantage when it comes to exploration. 
There is the added engine and propeller, but more importantly the twin 
screw boat can back down pretty much in a straight line that is very, 
very difficult to do in a single. At the low speeds typical of risky 
exploration of a cove the single screw boat is at a major disadvantage. 
In such a situation backing down in a straight line is almost impossible.

While exploring, if there is current coming from behind, especially if 
the current is strong one can get into major trouble so fast that you 
will be unable to counter it. I have gone aground with a single, where a 
twin screw with more speed would have been able to extract.

In 2 cases with twin screw boats I have backed down hard to keep from 
going aground with strong current from behind. Once while going into the 
Strawberry Channel south of Cordova Alaska and once at the entrance to 
the Summit south of Kake Alaska. In both cases the amount of backing 
down required was severe. The lesson is that strong floods or ebbs from 
behind leading into areas of shoals requires unfailing attention and 
instant reaction. You should not assume that the current is running down 
the deepest part of the channel. In fact it may be attempting to flow up 
and over a shoal directly in your path and if given some inattention you 
can be pushed right up on it.

This business of strong currents argues for waiting for times around 
slack water. Unfortunately, this may not be practical, but you have been 
warned. For single screw boat especially I would have a stern anchor 
ready for immediate use and someone to deploy it.

Using a powered dinghy to explore ahead of the big boat may be the best 
tactic.

Regards,
Mike


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Capt. Mike Maurice
Beaverton Oregon(Near Portland)