Cucumbers wash, clean, halve lengthwise and remove seeds. Cut them into diagonal pieces about 3 cm wide (each half about 8 boats). Whip cream and 1 pinch of salt until stiff. Season to taste with horseradish and distribute into the cavities of the cucumber boats. Grind pepper on top. Cut the salmon into strips, also distribute. Serve garnished with lemon and lime julienne and thyme leaves