It's not all that clear just what advantages phaser arrays have over phaser banks; at first I thought an array was like hundreds of old style banks joined together, giving hundreds of times the overall firepower. However, if that was the case then phaser arrays should be as long as possible - the ideal weapon would be one gigantic phaser array that went all around the ship! But the trend these days seems to be for larger numbers of smaller arrays, which contradicts this idea. So I've tried to think up realistic advantages to be gained from using phaser arrays; many thanks to the members of rec.arts.startrek.tech for their rather lengthy debate on this issue, which provided a great deal of help in this area.

One problem with the Ambassador is their relative rarity. Starfleet generally seems to use today's super ships as tomorrow's workhorse, so really we should see lots of Ambassadors out there - but we don't. My guess is that the ship has been phased out by the Galaxy/Nebula combination, with the Galaxy as super ship and the Nebula as workhorse. I suppose that Starfleet might also have experienced some problems with such an innovative design and been forced to retire most of the ships early, though I'm reluctant to say that any Enterprise might have suffered from such problems.

As with many ship classes, we know remarkably little about the Ambassadors. Yet I can't possibly believe that a 24th century databank wouldn't know details such as the size, mass, number in service, etc. Hence, I've been forced to speculate a lot here.

All the images are taken from "Yesterday's Enterprise", which as far as I know is the only time we've seen any good close-up views of the Ambassador. However, this leads to something of a problem. Rumour has it that the Enterprise-C model was broken somehow after the episode was made - I don't know how, somebody may have dropped it or it may just be that the battle damage put on for the show made it unusable. Whatever the reason, the makers built a new version of the Ambassador which was used for all future appearances of the ship. And this new version was significantly different. The first appearance was as the USS Yamaguchi in the DS9 pilot episode "Emissary". Compared to the Enterprise-C there are many small changes :

• The Yamaguchis saucer section and nacelles are shifted back by about 6 metres.
• The Yamaguchis deflector dish has a darker spot of some sort in the middle of it.
• The lifeboats have been re-arranged on the saucer section.
• The Yamaguchis sensor dome sits on another structure which is absent from the Enterprise-C.
• The Yamaguchi has a cap on top of and beneath the bussard collectors.
• The Yamaguchi has a third shuttle bay located on the 'overhang' at the back of the Engineering hull.
• The aft end of the Yamaguchis engineering hull is broader.
• The Enterprise C's impulse engines glowed blue, the Yamaguchis glowed red.

Explaining the Yamaguchi variant is the thrust of some of the notes on my own entry for the ship.