Application of a new type of annular shaped charge in penetration into underwater double-hull structure

•A new type of annular shaped charge was utilized to enhance penetration performance into underwater structures.•Underwater tests of double hull subjected to shaped charges with annular and spherical segment liners were conducted. Damage characteristics of two layers subjected to these two shaped charges associated with underwater explosion were compared and analysed.•The maximum dimensions of the crevasse and the deflection of first layer subjected to annular projectile associated with underwater explosion were 2.6 and 1.3 times than those by EFP. As for the second layer, although the annular projectile partially penetrated into the shell, it caused a larger plastic deformation than EFP.•The new type of annular shaped charge caused more severe damage to the underwater double-hull than the traditional one.