Global-Regulation’s comparative law search is a great tool for exploring the implementing legislation of international treaties.
Here are the results for implementing legislation related to the Comprehensive Nuclear Nuclear-Test-Ban Treaty: https://www.global-regulation.com/search.php?year&country&province&start&q=%22comprehensive+nuclear+test+ban%22&advanced=false. There are results (as of April, 2016) for Australia, Canada, Russia, Sweden, Ireland and other countries.
The United Nations Convention on the Law of the Sea (UNCLOS) national legislation can be viewed here: https://www.global-regulation.com/search.php?year&country&province&start&q=convention+on+the+law+of+the+sea&advanced=false. The results show laws by Russia, Switzerland, Germany, Czech Republic, Estonia, Tonga and many more (often about different aspects of the implementation).
Other treaty legislation can be found by typing in the name of the treaty on the search page. To filter down to specific implementing legislation the country filters on the left can be used, or the advanced search feature.