The Seafarers of Catan expansion pack is an addition for the original Settlers of Catan board game. You must have the original game to use the expansion pack. The Seafarers expansion pack allows the addition of two more players, so instead of 4 players you can have 5 or 6. While players noted that the additional players make the game longer, they enjoyed the challenge that more players added and did not consider longer play a problem. The expansion pack also adds complexity and more elements to the original.

The Seafarers pack includes 14 additional edge pieces that expand the original board. 24 more hexagonal tiles, 12 harbor markers, 10 number markers, 8 victory point markers, 61 wooden ships and a rule book.

The rule book contains "maps", or different ways in which the board may be set up for play. Unlike the original game, the set up of the board is not random. While it can be set up in different ways, you use the "maps" to determine the set up. Another difference is the gold hexes which are akin to wild cards. Gold hexes allow a player to choose which resource he wants rather than receiving the resource based on the hex.

Players in Seafarers can build ships which must be placed next to a city or another ship. Sea lanes are formed with ships and count as roads. A player can get a longest road card with a sea lane. Sheep, which usually were overabundant at the end of the original game, can be used for ships. The relationship between ships and roads can be a bit confusing. You can't connect a ship to a road, although ships are somewhat analogous to roads.

A pirate ship has been added to the game which acts much like the robber in the original game. The pirate ship is black and players cannot cross the hex that the pirate ship rests on. The pirate ship can also can take player resources.

All in all, Seafarers follows the rules of the original game fairly closely. It adds less strategy than the Cities and Knights expansion pack, which some players prefer. The two expansions can be used together for 4, 5 or 6 players.

There is some complaint among players that the Seafarers Expansion pack changes the paradigm of the game because the board is no longer random. However the scenarios, while removing the random factor, give the game a more balanced feel. They also offer victory conditions, not present in the original game, which many players do like.

For more advanced players this Settlers of Catan expansion pack offers a new approach and for less advanced players it follows most of the rules from the original game so that it is not difficult to learn. The majority of fans of the game approve of Seafarers with very few reservations, the biggest complaint being the scenarios as opposed to the random board set up. Game reviewers gave the Seafarers Expansion Pack overall positive reviews.