The Seafarer 31 Mk I represents a significant milestone in the evolution of American fiberglass boatbuilding, marking the moment Seafarer Yachts transitioned from an importer of Dutch-built hulls to a primary domestic manufacturer in 1965. Designed by the legendary William H. Tripp Jr., this 31-footer was envisioned as a versatile racer-cruiser capable of handling offshore conditions while remaining manageable for a coastal-cruising family. Its aesthetic is defined by a distinctive clipper bow and a graceful sheer line, features that distinguish it from the more modern-looking, fin-keel McCurdy & Rhodes designed Seafarer 31 Mk II that followed in the 1970s. As one of the early "plastic classics," the Mk I helped define the era of the sturdy, heavy-displacement fiberglass cruiser, blending Tripp’s penchant for performance with a robust construction philosophy.
Seafarer 31 Mk I Sailboats for Sale & Market Overview

- Make
- Seafarer
- Model
- 31 Mk I
- Builder
- Seafarer Yachts
- Designer
- William Tripp Jr.
- Number Built
- Production Year(s)
- 1968 - 1974
Below are the most recent Seafarer 31 Mk I sailboat listings (up to 10).
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| Source | Year | Make | Model | Price | Cabins | Heads | City | Country | Listing Date | |
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DISCLAIMER: We are not affiliated with any external listing websites in any way. We simply aggregate publicly available listings to make it easier for buyers to find sailboats for sale. We cannot guarantee the accuracy of the listings, so please verify all information with the seller before making any decisions.