SCAMP: “Mini microcruiser” with CNC kits available
Car-toppable catamarans: Nacra 4.5, Dart 15, TOPCAT, Pixie (home build)
Lunar distance: Find longitude based on the position of the moon (given an almanac of positions predicted in advance)
RYA (Royal Yachting Association) (UK): Sophisticated program, generally well-regarded
ISSA (International Sailing School Association): Fairly widely recognized. No renewal required
IYT (International Yacht Training): US/Canadian alternative to RYA. Offers separate recreational and professional certifications. Must revalidate every 5 years (fairly cheap/easy)
ASA (American Sailing Association): US Coast Guard approved, shorter courses, less widely recognized outside North America
ICC (International Certificate of Competence): EU effort at a standardized credential. RYA, ISSA, IYT can issue. Must renew every 5 years.