Do it in a Jabiru...why not. Been done in a Victa 115*, AA Trainer 100? and other assorted 'smallies' J Johansson's global jaunts spent huge amounts of time over water,too.
With the Jab, route planning would be the prob re range, I guess. Might have to circumvent the Pacific via Kamkatcha and Alaska.
NO GPS and all the goodies either in the 'good old days" and I can attest that clock, compass, map, ruler and pencil still works.
*If I remember his story correctly, the Victa got shipped Japan to Canada.
And the AA guy Tholstrup? had just got his PPL in it, and off he went !
Bravo all those of adventurous bent.!
Now who will lend me a Jabby...and a bucket of $$$s