Is a swim cap a device that makes you swim faster?

My hair is thick but medium length. I train without a cap but race with one. I notice immediately that my distance off the wall is greater when I have a cap on. Even more so with the new Speedo thick/stiff cap.

My hair is thick but medium length. I train without a cap but race with one. I notice immediately that my distance off the wall is greater when I have a cap on. Even more so with the new Speedo thick/stiff cap.