Sailing Performance & Handling
On the water, the Tes 678 BT is characterized by its stability and predictable manners rather than raw racing speed. Utilizing a swing-centerboard (miecz obrotowy) and internal ballast, the boat carries a relatively high displacement-to-length ratio for a 22-foot trailer-sailer. This weight, primarily concentrated in the bilge, gives the boat a "big boat" feel in a seaway, resisting the twitchiness often found in lighter dinghy-style cruisers. According to technical specifications provided by Tes Yacht, the boat typically carries a fractional sloop rig that is easily managed single-handedly, with all lines led aft to the cockpit.
While the high freeboard provides exceptional dry sailing, it does introduce a degree of windage that can be felt when maneuvering in tight marinas under power. Under sail, the boat tracks well due to the profile of its centerboard, though it performs best on a reach. Upwind performance is respectable for a shallow-draft vessel, provided the centerboard is fully deployed. In heavier air, the boat remains stiff, a testament to Siwik’s focus on safety and family-oriented cruising. The transition of the 678 into the Tes 720—a sibling model built on a slightly extended version of the same hull—demonstrates the versatility of this hull form, which was lengthened primarily to improve the exit of water at the stern and increase the theoretical hull speed.
Interior Comfort & Variations
The interior of the Tes 678 BT is often described as "Tardis-like" by the marine press, as it manages to fit amenities into a 6.78-meter hull that are rarely seen in this class. The cabin features a full 1.75 meters (approx. 5'9") of headroom, a remarkable feat for a trailerable boat. The layout typically includes a double V-berth forward, a convertible dinette in the salon, and a longitudinal galley. Unlike many of its contemporaries, the 678 BT includes a fully enclosed head compartment, a critical feature for extended family cruising.
Variations of the interior often depend on the specific production year and whether the boat was commissioned for the charter market or private ownership. The "BT" version specifically refined the woodwork, moving toward lighter oak or mahogany finishes to enhance the sense of space. Its sibling, the Tes 246 Versus, evolved from the same design language but offered a more "European" modern aesthetic with a plumb bow, whereas the 678 BT retains the traditional raked bow that facilitates easier boarding from a beach or low dock.
Known Issues & Buyer’s Checklist
Prospective buyers of a used Tes 678 BT should focus their inspection on the mechanical systems unique to swing-keel boats. The centerboard lifting mechanism—including the stainless steel cable, pulley blocks, and the manual winch—is a high-wear area. Any resistance or grinding during the lift may indicate a misaligned board or a frayed cable that requires immediate replacement to avoid a "board drop" scenario.
Another area of concern is the deck core around the mast step. Because these boats are often frequently rigged and unrigged for trailering, the mast step can endure significant lateral stress; any signs of crazing in the gelcoat or soft spots in the deck should be scrutinized for moisture ingress. Additionally, the rudder blade and its pintles should be checked for play. Given that many of these boats spent their lives in the shallow, sandy waters of the Mazurian lakes, the leading edge of the swing-rudder often shows signs of grounding wear that may require epoxy fairing.
Community & Resources
The Tes 678 BT benefits from a robust European following, particularly in Poland and Germany. While there is no single English-language "class association," the brand is supported by the manufacturer's long-standing presence and a network of regional dealers. Technical support and original parts are often sourced through Tes Yacht Canada for North American owners, who provide documentation on the transition from the 678 to the newer 246 and 28 Magnam models.
The Verdict
The Tes 678 BT is an overbuilt, high-volume pocket cruiser that excels in versatility, offering the ability to explore shallow estuaries one weekend and be trailered across the country the next.
Pros:
- Exceptional interior volume and headroom for its length.
- True "beachable" capability with its swing centerboard and rudder.
- Enclosed head compartment provides genuine cruising comfort for families.
- Sturdy construction with a focus on stability and safety.
Cons:
- High windage due to the tall freeboard can make docking challenging in a breeze.
- Not a "sport" sailor; prioritizes comfort over high-performance tacking angles.
- Heavier than many 22-foot competitors, requiring a more substantial towing vehicle.





