xort, yes, I've poured over the charts for a good portion of our trip; Unfortunately, the bottom isn't marked for a number of those harbours and coves. For example, Dunk's Bay is on Canadian chart 2235 and shows a gradual shallowing from 12 down to 5 metres. I know, from 34 years of owning a cabin near there, that it's a sand bottom out as far as I can swim. However, I also know the Niagara escarpment from shore... if you've ever looked into its depths, you can see it's just solid rock. This is why I asked the harbour master for some local knowledge and advice on where to anchor. I don't believe he was trying to scare me as I already told him we're paying him a visit. He *may* have been suggesting we do something like CorvetteGuy describes but he didn't mention the rebar... I think I'm with CorvetteGuy though, I don't know how well I'll sleep.
As for the Otter Islands... that's what I thought. However, he tells me that between the islands it is shallow and somewhat protected.
I must wonder if he's assuming I'm just anchoring for lunch instead of overnight. That might be a rational explanation for his recommendations.
Anyway, as for the bucket, I have to believe he's thinking that I'll lodge it in a crevice in those massive Georgian Bay rocks.
Lastly, xort, you mentioned the Cove Island Harbour. Yes, it's on "the plan" and detailed well in the Ports book. It, too, does not have the bottom marked but we've found good information on that already. We're also considering Club Harbour (instead of Rattlesnake Harbour) as a stop on our way to Killarney... if we make it that far before we run out of time. Also, Dunks/Little Dunks Bay and BayCabot Head (Wingfield Basin) for overnighters from Tobermory. Only Wingfield Basin has the bottom marked on the chart.