Merial Currer runs Patriot Scuba, an Occoquan, Va., shop that takes adventurous Washingtonians diving in one of two quarries within a short drive of the city. Two years ago, her son Will, an Army employee who studied cybersecurity in college, told her about ActivTrak, new software that would allow her to monitor her employees’ desktops. She thought it would be a nice way to manage the office when she was away.

Currer has told her four full-time employees that she monitors their computers, and they don’t seem to mind — she says she has not received pushback and mainly considers her use of the software a precaution to ensure that her workers who interact with children in their daily routines stay off inappropriate websites.

“We’re a family-oriented business, so we want to make sure our employees are on family-oriented websites,” she said.

Cheap monitoring tools such as ActivTrak, Spector 360 and Workexaminer.com have made snooping possible for even the tiniest enterprises, allowing managers to track employees’ desktop activity — covertly, if they choose.

The danger is that managers might rely too heavily on the technology, jump to conclusions and use it to avoid more meaningful conversations with their staffers.

“With any kind of performance management technology, in the absence of good managerial skills, it can be really dangerous,” said Ken Oehler, global engagement practice leader at Aon Hewitt, a human capital consulting firm.

Developed by Dallas-based Birch Grove ­Software, ActivTrak gives managers up-to-the-minute screen shots of what employees are doing on their computers, displaying the images on a dashboard resembling a security guard’s camera display. Managers can send pop-up boxes that appear in the corner of an unwitting slacker’s screen, admonishing him or her to get back to work. Spector 360, a monitoring service offered by Florida-based Spectorsoft, allows employers to detect specific keystrokes, alerting an IT manager and capturing rapid-fire screen shots as “evidence” when an offending keyword is added to a text document or an e-mail.

Employers can get regular productivity reports showing what employees are doing with their time: breakdowns of which websites they spend the most time on and whether their browsers are open. And monitoring doesn’t have to stop when an employee leaves the office. Employers who want to track those working remotely can use ActivTrak’s “invisible remote installer” to install the service on any computer on the company network. As long as managers have a network connection and administrator rights to a given computer, they can access the machine without an employee’s knowledge.

This sort of employee monitoring is nothing new in the Internet age. A 2007 survey of 304 small and large businesses by the American Management Association and the ePolicy Institute found 45 percent of employers tracking content, keystrokes and time spent at the keyboard.

“Even if your boss says you’re not being monitored, everybody should just assume you’re being monitored,” said Nancy Flynn, founder and executive director of the ePolicy Institute, a consulting firm that trains businesses on electronic compliance issues.

The emergence of new technology means that employee monitoring is not just the purview of government agencies and large corporations — small businesses can monitor their employees at little or no cost. ActivTrak comes free for those who need only three “agents,” the company’s lingo for a monitor placed on a single desktop. It costs $34 a month to monitor five employees, and larger companies can pay $199 a month to monitor 50 workers. Most of the employers that use the service don’t pay for it: Of 31,203 companies around the world that use Activtrak, only 7 percent use one of the paid models.

But the way the software is used — whether to tell employees that they’re being watched and what to do with the data that ActivTrak generates — is up to the manager. ActivTrak encourages its users to tell their employees that they are being monitored, but the company says it is aware of clients who do not do so. For others, just the specter of being watched is enough to scare their employees off Facebook.

ActivTrak markets itself as a tool for increasing productivity, but its effect on company morale depends on how managers use it. Some employees, such as those in financial services, expect their activities to be under a microscope for regulatory reasons, but in other cases monitoring can drive a wedge between manager and employee.

“Right at the heart of all of this is trust. Does the employer trust the employee? What sort of message does it send that they need to monitor their desktop?” said Oehler, the Aon Hewitt specialist.

“The technology in the hands of a bad manager could be really devastating. In the hands of a good manager, it could be really useful.”