"Obstruction" is already defined. A continuing obstruction is implicitly an obstruction that hasn't ceased being one. Is there really a need to try and define it further? 

Obstruction An object that a boat could not pass without changing course substantially, if she were sailing directly towards it and one of her hull lengths from it. An object that can be safely passed on only one side and an area so designated by the sailing instructions are also obstructions. An object that cannot be safely passed on either side and an area so designated by the sailing instructions are continuing obstructions, A boat racing is not an obstruction to other boats unless they are required to keep clear of her or, if rule 23 applies, avoid her. A vessel under way, including a boat racing, is never a continuing obstruction.

Aldo, is see you have added the word "continuing" to the quote of the definition of Obstruction. Is that your suggestion or have you got a different rule book?

Absolutely no other book, just answering to the post: what I think it would be a proper definition of the "continuing obstruction"

Terminology on Page 1 of the rule book tells you how to understand the meaning of continuing obstruction.

Obstruction is defined, but continuing is not. Therefore continuing is used in the sense ordinarily understood in nautical terms of general use.

So a continuing obstruction is an ongoing obstruction or obstruction without a break in continuity.

The island in your picture would appear to be a continuing obstruction, the boats are not.

Thanks you all so much !!!!

Despite how the term continuing is used in 'general use' (see Terminology), I think Catalan Benaros does have an interesting and valid question.

How do you actually 'apply' that word?  What is 'ordinary use' to you?

Here's how I use the term 'Continuous', when I think of obstructions.

As mentioned, in an ordinary sense, 'a continuous obstruction' is one which doesn't come to an end when a non-continuous obstruction would do.

Well, the definition of 'Obstruction' says that it is an object which from one hull length, requires a substantial course change to avoid it.

After making that substantial course change and avoiding the obstruction (say, a position abeam), can the boat turn back and resume her original track on the other side of the obstruction??

If the answer is no, then then to me it was a 'Continuing Obstruction'.

What do you think?

As I mentioned earlier, "Obstruction" is already defined. If you are still obstructed as you pass the object already qualifying as an obstruction, then surely it is a continuance of that original obstruction, hence in the ordinary use of language, it's a continuing obstruction? There is no need for further definition , or to put physical boundaries of distance, boat lengths, a zone etc.... around its continuance. It's a continuation until the time it is no longer an obstruction

Read USA Appeal

Thanks Mark, i have the USA Appeal....i can not find a similar case, but i´ll keep reading it.
THANKS !!!!!

well, good question. Being the starting pin NOT surrounded by navigable water, section C should apply. And being continuous, no 18 but 19...

You just don't want me to sleep tonight.

By the direction of the flag you drawn, i presumed a start downwind; boat on port tack,  along the pier: continuous

Boat on starboard, as per your flag and arrow: ,if you consider the tip of the pier as mark, guess 18 might be ok, by the book;  though it's  quite difficult to know for anybody, boats included, if there were a 18.2 or not, specially if boats were waiting for the start since some time.

Myself, being the tip of the pier  possibly a mark, but just behind the tip, it's not, I would apply 19.

Reading (actually: dissecting) the definition of "mark":

Mark An object the sailing instructions require a boat to leave on a specified side, and a race committee vessel surrounded by navigable water from which the starting or finishing line extends.

If  it's required, by the definition,  that the sailing instruction have to specify  which side to leave the object, in order to  consider it a "mark", i believe that such object should have the physical possibility to be left also on the other side. 
A pier: no option. That's why I would still consider the pier an obstacle only.

Veeeeery much my opinion.
And after this upcoming sleepless night, who knows...
 

The whale has R.O.W.

Hahahahha

Is it a starboard tack whale or a port tack whale?