Why didn't the Umayyad Caliphate/other Islamic Empires colonize

they lacked naval technology

>>2377017
What ships were they using to sail around all over the Indian ocean and down the east coast of Africa to Zanzibar/Tanzania?

>>2377008
Europeans sailed out of Europe to the America's because they were literally looking for a way to access the far east without going/trading through the Islamic world.

There would have been no incentive for the Islamics to do so. Humans don't like going on incredibly dangerous journeys where half your crew dies and the rest all lose their teeth unless there is a huge reward. Long sea Journeys until about 1660 were just ridiculously dangerous.

>>2377021
Fast coastal ships for warm and relatively calm waters.

An Atlantic squall would have ripped them in half.

>>2377017
there have been record of islamic merchantman sailing as far as china though i suppose an invasion is a different thing

>>2377035
I don't have a citation, but I recall reading that Islamic traders sold turtle shells from species found in the Torres Strait region between New Guinea and Australia, which indicated some kind of trade between the merchants and the natives of that region.

That's quite a ways to sail from Java.