Hi All,

We have developed an online marina database with some unique
capabilities based around content, communications, and community. It's
all about sharing knowledge among the community of marinas and boaters.
The database has free access for anyone. It's called ActiveCaptain
(www.activecaptain.com).
[...]

There exists a similar website: http://www.skipperguide.com
In difference, it is not focussing on facilities, but on all aspects
that may be interesting for cruising. The objective is to become a
online cruising guide, wrote by various people. This site is quite new,
at the moment mainly European waters are covered.

....and you don't have to register at all to use it

-Peter