The main technique is to shoot them with your cannons while you maintain a safe distance from their attacks. If they contact your ship, it will be damaged, and if they remain in contact, you will suffer more damage until you either escape or sink.
Unlike the enemy pirate ships, monsters cannot attack from a distance (the giant pufferfish can become larger to attack). However, also unlike ships they cannot be tricked into running aground on rocks. But overall, they are an easy way to get lots of doubloons and salvage, which are released when they die and sink.
Once you have a ship with cannons, practice hitting your targets at long range, accounting for their motion and that of your ship. When you aim your cannon, your ship will also turn that way, so learn to shoot quickly and steer away. You will have to hit the monsters several times (7 to 12 hits is common, depending on the monster). Beware of multiple monsters, or of pirates attacking at the same time -- sometimes the monsters will helpfully sink the enemy ships.
** The best place for fighting monsters is to the left and above Dragon Cove. They may also appear between Parrot Port and Golden Harbor.
You have to defeat ships and sea monsters and pick up the cargo that they leave behind when they sink.
The sea monsters have "health meters" just like the pirate ships. If you shoot them enough times, they die and release salvage that you can collect.
Nothing. Captain Crawfish was there. But you don't exactly do anything on Skullduggery island. You defeat Crawfih on sea.
I have defeated a sea monster, but there is more than one, so it depends which one you are defeating.
Yes. You can still sail and fight pirates and sea monsters, but there is little else to do except amass a huge fortune in doubloons. Be aware that you still lose doubloons if you are sunk, so you could be risking millions. Nothing to worry about once you have won.
Once you have the five pieces of the Treasure map, you can put them together to reveal the small, hidden island of Skullduggery, just below and to the right of the Pirate Outpost. You can visit there, but there is initially nothing to see or do. Once you earn enough doubloons (from sinking sea monsters, sinking ships, or trading), you can buy the Phoenix Warbird and defeat Captain Crawfish. When you do, return to the Governor to get the map and shovel you need to dig up the treasure hidden on the secret island.
Once you have the largest ship (the Phoenix Warbird), and hire the Cannoneer, you can defeat Captain Crawfish. Sail to the sea near Skullduggery to fight him. Once you win, return to Fort Ridley and the Governor will give you the location of the buried treasure (and a special shovel). Dig up the Buried Treasure on Skullduggery Island to win the game. (see solution at the related question)
here's the deal, YOU CAN'T DO THAT. you can sail out to sea on a boat, but you can't swim out to sea.
Skullduggery sea is in the bottom left on the map
The blimp is at Fort Ridley, the middle island, next to your ship/the sea. Hope this helps!
dont go in your boat just go in the water for a second and then jump out
It is definitely harder to fight a ship with more cannons than yours. But with practice, you can avoid many cannon shots. Except for Captain Crawfish, the pirates cannot repair their ships at sea. So if you acquire the skilled Shipwright (20,000 doubloons at the shipbuilder), you will have an advantage. You may wish to practice by attacking Sea Monsters above Dragon Cove. Unlike pirate ships, they do not shoot back.