A BETTER upgrade than the new oly 300mm f4?
Perhaps. Perhaps not. But for me I think so :-)
A hide for water birds, to zoom "with my feet". And a shorter - the ts apo 480mm, for a wider view. Though it might be to long, but it all depends.
Had planned to build a home made "Hidrohide" first - even bought all the materials - til I stumbled across "MrJan". The portability of the project (or lack of) was what kept me from building my own. Now I can inflate it on site in 5 minutes, and ready to go.
But the main thing up here (or down) is to keep warm in the waters after the ice on the lakes have melted away, late feb/mars. for that a dry suit is needed.
Thankfully we have no alligators/crocs or hippos...
the telt cover is home made of materials I already had.