the depth of the cavity 24 may be between about 30 and 6 mils t 1 may be from about 60 to about 110 mils it will be appreciated that the exact coating thicknesses at the various locations on the tip cap will vary depending on bucket size tip clearance requirements and the like this bucket tip surface feature impedes tip leakage loss without degrading the lcf and creep life of the bucket it will be appreciated that other bucket tip surface features are within the scope of this invention for example in fig3 the cavity 32 is defined by a smoothly curved surface 34 extending continuously from the suction side 36 to the pressure side 38 of the airfoil 40 forming a ridge 41 about the edge of the tip alternatively as shown in fig4 a machined ridge 42 could be formed in the tbc coating along only the suction side 44 of the airfoil or along only the pressure side of the airfoil not shown by simply eliminating one side of the cavity fig5 illustrates another surface feature in the form of a ridge or rib 48 machined or ground into the coating along the mean camber line equidistantly spaced from the suction side 50 and pressure side 52 of the airfoil 54 in fact any surface feature machined into the tbc coated bucket tip for the purpose of effectively reducing the tip gap over.