AH… I understand.
You were right to be wonder if it is possible to reliably structure the permalink like that, and I am sorry to say it is not. WordPress is not structured that way. A post (a boat in your case) can only reliably have a URL with the post type in it, such as:
http://myboats.com/boats/boat_name/
OR http://myboats.com/boats/boat_type/boat-name/
It cannot predictably have one like:
http://myboats.com/boats/catamaran/boat_name/
OR http://myboats.com/boats/boat_type/catamaran/boat_name/
Why I didn’t get what you wanted earlier I do not know, for which I apologize. The issue is that Taxonomies are stored as arrays and can have multiple values, even if you only ever use one. If you can keep the taxonomy term down to one term per post, then it would become predictable. The other issue is that our search can only go to the archive page, even if that page might have only one result, and so the URL cannot have the name of the boat, so, in the above example, the URL of the results page can only ever be as long as:
http://myboats.com/boats/catamaran/
OR http://myboats.com/boats/boat_type/catamaran/
OR http://myboats.com/boat_type/catamaran/
WordPress allows you to include or omit the taxonomy name in the URL. Generally, you should avoid having a single taxonomy used by more than one Post Type. In the last example set, you can see that, as boat_type
should only belong (in this case) to boats
, boats
is not necessary in the URL, but is good from an SEO point of view.
I hope I now understand you correctly and have this right?