score:11
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.
Upvote:2
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.
https://en.wikipedia.org/wiki/Invasion_of_Jamaica
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...
https://en.wikipedia.org/wiki/France_Antarctique
https://en.wikipedia.org/wiki/Capture_of_Recife_(1595)
https://en.wikipedia.org/wiki/Dutch_Brazil
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.
Upvote:3
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.
Upvote:3
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.