To those people who have yet to acquire the game, or those yet to punch out the pieces - don't punch out the 16 Location tiles you don't need (You don't need the ones that are yellow on both sides if your language is English, blue if German) and don't punch out the spare sets of 3 Frigates and 4 Spanish defenders. Those un-punched sheets can then be placed under the insert.
If you have already punched out the game but still have the sprues, those pieces can easily be slotted back in place for storage under the insert, as described.
I just had to fish my sprues out of the bin!!