Long stay visa for Italy

[Gnilias]

Hubby and I are dual Australian and British citizens with a British registered, EU VAT paid boat. We are mainly living aboad, interspersed with trips to Australia and the UK to visit family, and we are currently cruising in Greece with a Greek Class D visa.
We are planning to head west in the Med during 2025 and to cross the Atlantic around December 2025.

Our original plan was to over-winter in Tunisia and spend time in Tunisia, Morocco, UK and Australia to manage our Schengen days. This will work but requires careful monitoring, and as Pantaenius have declined to insure us for more than 6 weeks cruising in Tunisia, we are still looking for an insurance company that will cover the winter in Tunisia.

The other possibility we are considering is to over-winter in Italy. For this to work well for us, we'd need to get a visa to allow us to stay in Italy for more than the Schengen time frame. This is the area I'd like your help with.

I'm aware of the bilateral agreement between Italy and Australia, but I gather that this is not fully accepted in all ports in Italy and a complication for us will be that we want to spend our time in Italy before using Schengen days, not afterwards.

I'm also across the idea of being as crew, not checked in, as outlined in the Sailing Helios Youtube channel and recently referred to in this forum, but ideally we'd like to avoid the constraint of not being able to spend a night on land.

So it seems to us that the best option, if we are eligible, is to apply for a long stay visa in Italy. We are retired and can demonstrate income to support ourselves, health cover etc, as required. Our intention would be to leave Italy before clocking up residency for tax purposes, as we prefer to keep life simple and just be resident in one country (Australia) for tax purposes.

We could either apply for a winter marina contract or an annual contract in Italy.

So I'm consulting the Brains Trust. Has anyone else any recent experience of getting an Italian long stay visa? I've heard that a marina is no longer sufficient proof of residency, but am not sure whether this is correct? Can anyone recommend a good agent, website, or share personal experience of what worked or didn't work for you? Thanks