The vids description on YouTube reads as follows.

Trimaran with hydrofoil. However few sailors appreciate that high speed sailing is only possible with high stability. This is a huge hydrofoil trimaran. This configuration ensures that you always sail with all four foils.

The TF10 hydrofoils are daggerboards in a so-called Z-shape. Glen Roberts selfmade Hydrofoil trimaran 15 year project test run 2012Description Epoxy glass plascore skin construction. Sailing in the Marlborough Sounds New Zealand during January 2014.

This was then used in the hydrodynamic design of a fully planing trimaran with. In such a case the foil would be. Firstly a mathematical model was developed to calculate the equilibrium planing conditions of a planing trimaran.

The second reason would be when one is considering asymmetrical foils or even hydrofoils for the reason of developing extra lift from the leeward ama. The main one is when one is sailing a VERY light trimaran probably of all carbon fiber will high buoyancy amas that will frequently be pushed to sail on one ama. The Canadian-built hydrofoil vessel Bras dOr A hydrofoil ferry.

Of course high speed requires that the boat should have low drag and this is achieved with the narrow hulls of the trimaran and the lift of the hydrofoils. Sailing a fast hydrofoil trimaran is easy if it is designed well like this CATRI. The CATRI 24 provided a really comfortable 90 hydrofoil stabilised platform upon which to take to the sea.

Model tests and numerical simulations investigate the application of a hydrofoil supported water craft Hysuwac hydrofoil system for trimarans drawing on experience for foil-assisted catamarans. While foils are demonstrated to effectively decrease the resistance of trimarans a comparison shows that a catamaran with similar displacement and same speed is still superior to the trimaran with or without foils. This is a gigantic ocean going vessel that can travel almost 40.