wajer 38 s foil assist

July 16, 2020 | Article

Improved 38 and 38 S with foil assist

We’re very proud to introduce a fully upgraded version of our esteemed Wajer 38 and 38 S. Next to aesthetic improvements, these models are now being tested with foil assist. The brand-new adaption of foil technology ensures a totally different sailing experience, meaning less slamming, enhanced comfort and better performance. The foil aid is placed amidships on the hull and literally lifts the boat, greatly improving sailing comfort and reducing fuel consumption, while still reaching top speed. Preliminary technical research also has shown that the foil assist reduces fuel consumption with 10-20%, while maximum speed increases with 3-6% at equal power.

Improved technology

This new foil assist on the Wajer 38 and 38 S was developed by Van Oossanen Naval Architects. Sailing these foiled Wajers makes for a more comfortable ride as they literally fly over the waves. There’s less slamming on the water which means a drier ride, as it reduces spray considerably. In addition, she sails more stable and faster because the boat has less resistance. Preliminary technical research also has shown that the foil assist reduces fuel consumption with 10-20%, while maximum speed increases with 3-6% at equal power.

The foil assist application is currently still in the testing phase. The results of the tests will be included in further development and application of the foil assist technique.

Foil Assist

“We constantly develop new technologies to improve our fleet”, says Dries Wajer, managing director of Wajer Yachts. “Next to aesthetics like materials and practical enhancements, we wanted to take a serious step in upgrading the performance of the 38 models. With adding the foil assist I believe we have”. For a number of years Van Oossanen Naval Architects has done research on the application of a hydrofoil placed amidships on planing hulls with prototypes. The goal is not to go into a hydro foiling “flying mode”, but to carry part of the boat’s weight on the foil, rather than on the bottom, hence it is called “Foil Assist”. With Foil Assist, it is possible to increase the speed and comfort on a yacht. Patent is pending on this specific system.

How it works

The Foil Assist wing is made from solid stainless steel. It is a rather small, passive device, which is placed on a fixed position on the yacht. Foil Assist extends below the hull, but less so than the IPS units of Volvo Penta, which are the deepest part of the yacht. Foil assist is built to resist the forces when making fast corners and dampens the pitching motions in waves. Carrying the weight partially on a submerged wing rather than entirely on the waterline, reduces the effect of waves on the boat, as the orbital motion in waves diminishes with depth. Furthermore, with the hull not lifted completely out of the water, the yacht will behave like a normal planing yacht with predictable behaviour, and the weight requirements are not nearly as stringent as for a fully hydro foiling boat.