Bought and watched. Here's my report:
The movie starts with a very short flashback (at least we assume it's a flashback because the sequence is in black & white) with a wide shot of the Titanic that looks like it was taken from the 1943 German movie. It then cuts to Tara Fitzgerald on the deck of the ship - a man tries to seduce her with a smile but she quickly looks away. There's no dialog but a song:
"The finest ship that sailed the sea
Is still a prison for the likes of me
But give me wings like Noah’s dove
I’d fly up harbour to the girl I love…"
The movie then switches to color and it's 1933. A young minister (played by Hugh Grant) and his wife (Tara Fitzgerald, on the deck earlier) visit an artist (Sam Neil) and the three sexually playful models living with him. The DVD cover and the taglines would have you believe the movie's a light hearted romantic comedy but it's actually an erotic drama about a reverend's wife finding her own repressed sexuality.
In it the Titanic is used as a clumzy metaphore for her "morality" that sirens will lure to an iceberg of lust and "sink" into an ocean of decadence. Except it's not really the Titanic since it sank in 1912 and the movie takes place 21 years later.
Here's a couple of screenshots:
http://img.villagephotos.com/p/2004-3/688227/tn_Sirens1.jpg
http://img.villagephotos.com/p/2004-3/688227/tn_Sirens3.jpg
http://img.villagephotos.com/p/2004-3/688227/tn_Sirens5.jpg
Not that bad a movie - a couple of interesting "thought provoking" scenes and Portia de Rossi and Elle Macpherson naked make this worth seeing. You can buy it for $9.99 on amazon or for as little as $3.50 thru some of their resellers.