Most British (and American) Ships of the Line from the late 17th and 18th centuries had long range forward facing guns called "Long Nines". These were cast iron, "9 pound" guns usually 8 or 9 feet in length used as a "chase gun" firing from the bow or stern of the ship. On the larger ships such as the classic British "Man of War", often entire broadside batteries were "long nines".
Most warships in the age of sail used long guns as chase guns; they weren't unique to the British and Americans. And a long nine-pounder was only a modest-sized gun, like you might find on a frigate. The heart of the fleet, the ships of the line, would have 24-pounder or 32-pounder long guns for the broadside battery. (During the Napoleonic Wars at the end of the 18th century, short-barreled "carronades" became much more popular, replacing many of the smaller long guns.)
This was part of the reason why the British fleet ruled the seas for so long. They could take out an enemy from a range so far the enemy could not shoot back.
Actually, this is the exact opposite of the strategy preferred by the British. It's true that back in the days of the Spanish Armada in the late 16th century, they preferred to hit at a distance with longer-ranged guns, but this approach didn't work out as well as hoped; the guns' accuracy and energy fell off much too quickly with range. By the height of the age of sail in the late 18th century, British ships preferred to close to point-blank range (one reason why short-range carronades became so popular). The keys to their naval superiority were better seamanship (leading to more efficient and effective ship handling), aggressive tactics (take the fight to the enemy whenever you could), and better gunnery, which for the British meant that their gun crews could pump out more shots more accurately than their adversaries could. The British believed that in a close-range fight, their ships could be relied on to deal much more damage more quickly than their enemy, to the point that they could board or otherwise force the enemy to surrender, and that any damage their own ships suffered could be handled and patched by their well-trained crews. It was a belief often confirmed in practice.
In this style of fighting, the main role of chase guns was either to slow down a fleeing adversary enough to allow the British ship to close for a short-range battle, or if pursued by a clearly superior enemy, to slow him enough to allow you to escape.
The British kept to this approach until the development of accurate long-range rifled guns forced them to abandon it.