Would I use avistado, or regular past tense?

Question

Otras historias tradicionales dicen que Nueva Zelanda fue avistado por una larga nube blanca que colgaba sobre la tierra.

Answer 1

What's the original phrase in English?

Other traditional stories say that New Zealand was sighted by a long white cloud hanging over the land. - oceanbelcher, May 1, 2011

Answer 2

Nueva Zelanda or Nueva Zelandia doesn't exactly mean that the name is feminine and it seems to be one of those countries that does not employ a definite article, however, if it is feminine in gender then it would be:

...Nueva Zelanda fue avistada por...

traditional passive voice

The past participle must agree in gender and number with the subject of the verb. In essence you are linking the subject and the past participle —as if it were an adjective— with the verb ser.

¡Bienvenida al foro!

Welcome to the forum!

As to your question the por used with the passive voice (Ser+participio+por+agente) usually means by. In your sentence it seems to mean through or by as in "recognized by a large white cloud".[not an agent] If not incorrect, (the por agente is optional) it is definitely confusing.

avistar

I would suggest using como. New Zeland was seen from far off as a huge white cloud. Or maybe parecer with a change in wording.