Excellent review (++). Permit me to make just one more tiny DRY suggestion to turn

# Ships - surely there is a better way to do this
my %p1ships = (
    cru  => { hp => 2, size => 3, ap => 1, loc => '', sym => '*', mc =
+> 0 },
    car  => { hp => 3, size => 5, ap => 2, loc => '', sym => '@', mc =
+> 0 },
    subm => { hp => 1, size => 2, ap => 3, loc => '', sym => '~', mc =
+> 0 },
    );

my %p2ships = (
    cru  => { hp => 2, size => 3, ap => 1, loc => '', sym => '*', mc =
+> 0 },
    car  => { hp => 3, size => 5, ap => 2, loc => '', sym => '@', mc =
+> 0 },
    subm => { hp => 1, size => 2, ap => 3, loc => '', sym => '~', mc =
+> 0 },
    );
[download]

into

# Ships
sub ships_init {
    return (
        cru  => { hp => 2, size => 3, ap => 1, loc => '', sym => '*', 
+mc => 0 },
        car  => { hp => 3, size => 5, ap => 2, loc => '', sym => '@', 
+mc => 0 },
        subm => { hp => 1, size => 2, ap => 3, loc => '', sym => '~', 
+mc => 0 },
    );
}

my %p1ships = ships_init ();
my %p2ships = ships_init ();
[download]