I have a textbook which describes various considerations colonists made in selecting sights for settlements. For example, it says that Jamestown was too swampy, so there were many mosquitoes and diseases and the water was not suitable for drinking. Among the various considerations, it says that settlers avoided placing their colonies near the coastline, because this would increase the danger of being attacked from the sea. Prior to 1730, were there any actual situations in which a colony, being near the ocean, was attacked from the sea? Did coastal locations benefit from being easier to defend against attacks carried over land?
4A little outside the range you're asking about, but pirates knocked over Monterey, California in 1818. en.wikipedia.org/wiki/…– JoeDec 17, 2012 at 13:43
2Another outside your timeframe is the bombardment of Fort McHenry in Baltimore by the British in 1813, the source of the lines about "rockets red glare and bombs bursting in air" in the Star Spangled Banner.– Peter WoosterApr 5, 2016 at 14:50
Here's one example: The dutch colony of New Amsterdam (on Manhattan Island, it's New York now) was captured by four English frigates sailing into its harbour.
The British are on the other side of this one, but the point stands. Here's one out of the time scale but the Battle of Nassau deserves a mention as the US marines' first amphibious landing.
The infamous pirate Blackbeard blockaded Charleston Harbor for a week in 1718 to extort the city for medical supplies. During this time he captured every ship they came across, robbing the passengers and holding them hostage.
In general you'd think there'd have been more of this kind of activity, but the British North American colonies were actually rather friendly to smugglers and pirates, as they were an important part of the trading network. From the Spanish perspective, it could have been argued that all of the non-Spanish North American colonies were illegal settlements and pirate havens.
St. Augustine, Florida was attacked and burnt in 1586 by Sir Francis Drake.
In an extension of the English Civil War into North America, St. Mary's City, Maryland and the farmsteads around it were plundered between 1645-1646 by Captain Richard Ingle in his ship Reformation, financed by Viginia treasurer William Claiborne, whom the Calverts had kicked out of Kent Island.
The Maryland colony was so depopulated that Cecil Calvert ( Lord Baltimore) had to search around for some new colonists, and some Puritans who had been kicked out of New England settled in Providence, a settlement that eventually became Annapolis. This came back to bite Calvert as these settlers allied with commissoners appointed by Oliver Cromwell who sought to take Calvert's charter away. In 1655, Governor William Stone sent an expedition up the Chesapeake to suppress this, but he was defeated at the Battle of the Severn. Calvert didn't regain full control over Maryland until the Restoration in 1660.
The English invasion of Jamaica, 1655, is an example of a fleet taking a poorly defended colonial city. They just had an ineffective battery and small colonial militia. Artillery depended on specialized personnel and maintenance, so there is a myriad of possible reasons for its ineffectiveness.
In South America, Brazil, before 1650, was invaded from the sea by France, England and the Dutch. They mostly aimed provincial (i.e. capitaincies) capitals, and overwhelmed defenses such as forts covering the bay entrances.
I do not expect north american settlers would know details about this, but it shows colonial invasions of a relatively large scale (head counts were in thousands not in millions...), and that European wars could mess with an overseas settler life...
Besides, as other answer points out, easy targets would attract pirates. Mediterranean cultures at that time still had to deal with Barbary Coast muslim pirates, so building "cities well protected or a little far from the coast" was in the zeitgeist then, even for small communities which could not hope to defend themselves against a full scale national navy invasion.