This version is much improved over the first edition of Spanish Main. My biggest disappointment is that it no longer supports six players. The goal is to be the player with the most gold (and silver) in your possession at the end of the game. The game can end by revealing all the unexplored tiles in the Spanish Main or by running the sailing deck out of cards.
There are two playing areas. The first is a representational map of the Atlantic. Here players move between their home countries (Spain and Britain), to the Spanish Main. The edges of the map cannot be crossed and the Azores form an unpassable block in the middle of the map. Ships have to physically land on another ship to engage in combat, unlike the first edition where combat could be started from across the board. There are no special squares on the Atlantic board such as ship wreck, or arrows to force additional movement. The second area is the Spanish Main. This area starts out completely unexplored. The first edition did not have rules specifying a specific layout of the tiles. The second edition requires the Mountain tiles placed in the center, the Hills tiles in a single layer around the Mountian tiles, and the Low Ground around them. The Spanish Main also must remain in the original shape, no adding tiles to the outside rows.
The Spanish Main tiles are designed so that as players reveal them, they match the edges of other tiles. Often a revealed tile will not match its current location. These tiles are placed to the side and the map now has a gap in it. In later turns, players can fill in the gaps with tiles that match. The tiles also have mines and treasure chests with gold or silver. Once players have found treasure to plunder, they must brave the cannons of the opposing country and return gold to their home country.
The English players make better raiders due to their maneuverability. The best hope for the Spanish is to cooperate when leaving the Main or wait until the English are too busy exploring. I've only been able to play the new version once. The winner was English, but second place was only a silver behind. The game rewards the first players back to their home country as all gold doubles. Depending how long it takes for the next player to get back for the gold doubling, one player is likely to have a much better ship. If the player is English, he is usually raiding the Atlantic to prevent the Spanish players from bring back gold.
In the four player game, there are two English and two Spanish players. While they cannot attack each other, they cannot give each other gold either. Thus, if the English players attempt to attack a lone Spanish player, only one English player will get any gold. This makes cooperation for raiding very tricky. Spanish cooperation is a little easier. "Let's both go out and help defend each other." This can work well, but the player who loses his gold is far behind and it can be tough to catch up.
Combat in the second edition now uses a die. Each player picks a cannon card. Reveals it to each other and roles an averaging die. The attacker gets +1 to the roll. If the numbers are tied then both sides lose a sailing card. If the winner is ahead by only one point, the loser loses a cannon card and the winner loses a sailing card. Winning by two points forces the loser to discard the cannon card used in the attack, the winner lose nothing. Winning by three or more points is the same as winning by two, except that the winner can choose to attack again. In this next attack, the attacker does not get the +1 again. This is much more fun than the first edition combat rules which really didn't work very well.