: In
: eastern Europe here are more illegal copies of our Hawk and Eagle model
: than real boats. Also there are numerous boats that are clearly copies
: with minor changes being sold as original designs.

If copies are being made in Eastern Europe, you have to take enforcement
measures in the country concerned, and under their implementation of the
international copyright conventions. Copyright law is similar everywhere that
is signatory to those conventions (except that the USA has rather more
stringent local legislation, which much of the rest of the world resents).

: My understanding of the law is that by registering an existing design you
: have immediate copyright protection

You don't need to register anything under most copyright law - if you publish
something, you have copyright. "Publishing" in this sense can mean as little
as showing it to one or two other people. Selling one boat clearly does a lot
more than that ...

: My question is can US copyright laws be enforced in
: foreign countries.

See above - many aspects of your copyright can be enforced, but some
aspects of US law probably can't. You can't do the enforcement in a US court.

: My assumption is that some trade agreements call for
: reciprocity of copyrights

Its not really about trade - copyright is a whole different legal area,
governed by international conventions which having nothing to do with
(for example) the World Trade Organisation.

In practice, if the illegal copiers are only copying in their own country,
and not selling outside it, then you would have to take an action against
them in that country, using local lawyers. This is going to be expensive,
since you'd need to do this in each country, and for each offender. It is
highly likely that there are other kayak makers in those countries who
are making cheap kayaks, and that winning a copyright action would simply
mean that the copiers were stopped, but none of your orginal designs
would be sold, since they would be more expensive than the local designs.
There is no benefit to you in enforcing your copyright in this situation,
whatever the morality of the case. If, on the other hand, these people
were flooding the US market with cheap copies, then you would have a
solid case which was worth enforcing.

Andy