#1 you will only get sweet spots graphics if your target is less than 800m broadside shot ,+ or - 15 degrees of 0 degrees gyroangle,That is aprox.90 degrees AOA.(angle of attack)range normaly less than 500m w/tube door open-navagation setup requirements.I close target to greater tnan 300m for time for torp to arm. Highlighting sweet spot,normaly,engine room. Resets TDC, to impact pistol,depth 3m depth.Book graphic must be displayed,in attack scope,O scope, or UZO view.IMHO.Saves fish,splits Lg.merchants in 1/2 one hit.She's going down