Attached Link: http://excalibur.renderosity.com/mod/gallery/index.php?image_id=1252461

Not necessarily a favorite tip but for new users exploring boolean modeling within Bryce here is a quicky tip like diolma's about  what can be done within terrain editor.

You load a simple b/w overhead type image of a boat hull cross section into terrain editor by 1)create terrain 2) click the "E" to go into terrain editor 3) click new 4) load the image described above then exit editor to return to main screen.

Lower the new terrain.  Duplicate, resize the copy on the X and Z axis smaller slightly, stack it on top of orignal terrain and repeat the process several times.

This image shows the original B/W image fm paint program, a simple stack of resulting terrains, and a simple shrimp boat model using this system.

Link is to an image where I used a more refined version of this model