Names do not have copyright protection (otherwise, it would have been illegal to have written a copy of the name “Snoopy” in your question and my answer without permission of the name’s copyright holder).
Names can be trademarked, however, and there are currently 11 “Snoopy” trademarks registered with the U.S. Patent & Trademark Office for such products as motion picture films, pre-recorded CD’s and DVD’s, video games, corn chips, gummy candies, books, playing cards, clothing, and so on. There are also several trademarks that use “Snoopy” as part of a phrase Snoopy Halloween
When a word or phrase is trademarked, it is illegal to market a competing good or service using the same (or a confusingly similar) word or phrase. This is to prevent consumers from being mistaken about which is which.
Names can not be copyrighted, but they can be trademarked. The name Snoopy is definitely trademarked. That means it can not be used commercially in any field of business for which it is trademarked.
Noting that Snoopy is trade marked. Howeve, trade marks only apply to names, phrases and logos for a particular company or product.
Therefore, if you used Snoopy and included a picture of Charles Schulz’ character, you ‘d be infringing.
If you use the name “Snoopy” to identify something else, you are within your rights. In fact there have been some musicians and others who have used the name. The word “Snoopy” is, after all, a legitimate English word of itself and so the Peanuts administrators can’t claim it’s highly original coinage.
There are lots of trademarks on the word “Snoopy” for use as games, stage shows, and on and on. You can write about Snoopy, talk about Snoopy, draw your own Snoopy pictures to hang on your refrigerator. You can not start a business with any “Snoopy” goods or services, or you will most likely be sent a “Cease and Desist” letter from Peppermint Patty.
You would have to do some research on the actual trademarks. Even if you have legal grounds for using Snoopy that does not infringe on the trademark, you may receive a cease and desist order or be taken to court. Iconix, I believe, is the current owner of Peanuts and related property and trademarks.
In order to keep a trademark, you are required to defend it. So they would likely proceed even if the name of the team and boat have nothing to do with the comics.
To avoid such headaches, you would be better off asking for the right to use it. Explain your reasons. They may decide to provide provisional use as long as it isn’t associated with their property.
As usuall, when dealing with legal issues, it would be best to consult a lawyer that specializes in the area (Trademark law in this case) before proceeding.
Snoopy Halloween I have an old wooden pull toy that says Snoopy on it. It is over 50 years old. I have always wondered if it was supposed to be the snoopy character (originally walked on four feet, not two) but it is colored like a regular dog, not white and black.