The Skip-Bomb package was put together by Pen32Win and you can find it in the following aircraft:
AF-TR B-25C/D Tokyo Sleeper
AF-TR B-25 C-1 Chatterbox
aftr_ddandhf
I've also put this into ALL of TR's B-25's (well, except the B-25's that are Doolittle Raiders) ... otherwise, all the US versions get the skip-bomb treatment.
It's really neat because Pen used D-bolt's 500lb_GP_c and modified it through some obscure art -or- lost black magic (or some really creative knowledge of how CFS2 works). Regardless, the "500lb_GP_c" now acts like a torpedo ... except it still looks like and drops like a 500lb bomb. I set up my DP with the "500lb_GP_c" in the first position ... followed by 3 regular "500lb_GP_a'" types.
I also set the DP up for "individual" triggers "blah, blah blah, 1, -1" so I have to hit my "enter" button 4 times to drop all 4 bombs. I like it like that because it lets me have just that little extra control over the drop times.
When I make my run, the first to drop is the "c" which does NOT explode on contact with the water (because it thinks it's a torpedo)... but following right after are #2, #3 and #4 which do explode and "walk" right into the target. If you have timed your drop properly, the 4th explosion is the #1 finally reaching the target. (As a torpedo ... it has to run through the water, but you really rarely see the wake because of all the other explosions.)
It takes a little practice to get your timing right ... but like any other form of attack, once you get your groove ... you're in like Flynn!
Hope this long winded explaination helps.