from what i remember, hobie is actually correct...
because the bridge will ultimately cross a towards pasil/mambaling part, it does need to be really high...otherwise, bigger ships can't go under it...except if they'll create a moveable bridge:
Moveable bridge - Wikipedia, the free encyclopedia
@jeremiahjay - that is correct...2 bridges...but if you noticed, ships from manila does not cross under the 2 bridges anymore...which does back then...this is because (as far as i can remember sa news sauna) they are re-reouted to take the other side of the bridges...bale, nag-U-Turn sila...tungod man atong manga-sangit ang barko, mag-collision (thanks Trans-Asia...stufu captains), etc...