While many services offering to renew your boat documentation are legitimate, those wishing to avoid higher costs should be extra cautious about letters arriving in the mail offering US Coast Guard documentation renewal.

In recent weeks boat owners have recieved official looking renewal notices via the U.S. mail. Those who made a closer inspection found these were not sent by the U.S. Coast Guard, but by a documentation service offering to do the legwork for a fee.

Because, some argue, the marketing effort too closely resembles official USCG communication letters and contain knockoff USCG logos, complaints began to sprout on social media. Alert subscribers passed these postings on to the Waterway Guide's editorial staff.

Subsequent calls by Waterway Guide to the U.S. Coast Guard, two weeks ago, launched an investigation into the marketing practices of some of these companies.

"The Coast Guard is investigating the situation. As the investigation is ongoing, I can't provide any details at this time," USCG Fifth District Public Affairs Officer Nathan Littlejohn wroten in email Wednesday.

Calls to one company named in various postings were not responded to by press time.

Meanwhile, the Boat Owners Association of The United States (BoatUS) Consumer Protection Department, is urging boaters with vessels having a US Coast Guard Certificate of Documentation to be wary of any letter arriving by US mail offering renewal.

That's because an increasing number of BoatUS members have complained that these letters direct them to websites that may be mistaken for the actual US Coast Guard Vessel Documentation Center located in Falling Waters, West Virginia, and appear to show a significant increase in the annual fee to renew US Coast Guard (USCG) documentation.

Meanwhile, BoatUS advises that while the USCG does send official annual renewal notices by US mail, other notices being received by members are not from the USCG but rather third-party companies whose name or return addresses may appear similar to that of the official USCG Vessel Documentation Center. Members of the half-million boat owners group report the letters look like “real” USCG communications. Some examples members have forwarded to BoatUS do not have any disclaimers noting that they are not official USCG correspondence.

While third-party companies may legitimately provide services to assist with vessel documentation renewals, the USCG’s own renewal process is simple for most vessels and the price, $26, is often much lower than what third-party services may charge. To renew, go to the USCG National Documentation Center website at www.uscg.mil/nvdc and click on “instructions and forms.”

To be documented, a vessel must measure at least 5 net tons and, with the exception of certain oil-spill response vessels, owned by a US citizen. Boats about 27 feet in length or longer generally meet the weight requirement.

If boat owners wish to file a consumer complaint about this or any other boating-related advertisement or company, BoatUS welcomes boaters to visit http://my.boatus.com/consumer/dispute.asp and click on “send us a complaint” button.

Boaters also advises boaters who may have received mail that they believe is misleading or deceptive may contact the US Postal Inspection Service at 1-877-876-2455 or through its website https://postalinspectors.uspis.gov.