Do all HK marina sailboats use fixed keels?

This is a bit of a blanket question. If it refers to today, then of course not.

Today HK has the usual range of sailing vessels one would expect to find anywhere there is a substantial and varied recreational sailing community. There are ocean-going keelboats - most these days fin-and-spade rudder or fin-and-skeg designs, though still a fair few old fashioned full keelers, with one or two with a drop-keel that is usually an extension to a ballast keel (a design form made popular by the excellent US CCA handicapping rule of the 1950s and '60s (excellent because it produced seriously good-looking boats). There are various classes of what are known as day-sailers (like International Dragons), some full keeled (Dragons), others fin keelers (Etchells), as well as some intriguing, purpose-designed full keel small craft for handicapped sailors. There is a slew of dinghy designs, all centre-boarders (though these days almost nothing survives that uses a steel dropkeel (though I think there may be one Finn around still). There is a very lively beach catamaran scene (Hobies, Darts, Nacras, etc.). And there is at least one recreational junk that still has sails and, if there's enough wind, actually sails - but unlike the standard da tuo (big-eyed chicken) design, which had a dagger board between foremast and main - the extant examples are full keel, internal ballast designs.

If the question is about the past, the problem is which past? In the early days of yachting in HK (say 1840s-1930s), the answer is that everything was a full keel, or external structural keel and internal ballast style vessel because that was the sort of recreational sailing boat one found everywhere there was recreational sailing. Even with a shift to smaller vessels that led to the founding of the Corinthian Sailing Club in 1890, long keel designs without centreboards remained the norm, the change being mainly ones of size (from whoppers to tiddlers) and draft (from, say, <2m to <1m).

By this time, elsewhere, drop keel dinghy designs, whilst still few, were around, perhaps the best known being the 1886 Dublin Bay Water Wag. And I mention that because the class history (though not HK's established yachting history) claims that by the time of the classes design update in 1899, there were already established "Fleets were also set up in Argentina, Australia, Japan, Hong Kong, the Persian Gulf, and in Kent, where they added a jib and small bowsprit." What happened to them I don't know because, as we shall see, by the post-WW1 period, there appear no longer to have been any drop-keel dinghies around.

That's because in instantly consultable HK sources the first mention in HK yachting history I can find of any centreboarders is in 1935 when two young HK government cadets (future senior public servants) "bought a centreboard dinghy". The source doesn't say whether locally or imported, but since one of the two, Robert Minnit, went on to design and get built a centreboard design of his own, the 15' 'Suicide Class' in Guangzhou, where the pair had been sent to learn Chinese, and that on their return to HK where there "was not any dinghy sailing", the implication is that it was imported and that ,until 1935, there were no centreboard sailing vessels in HK except those traditional Cantonese junk designs that used a dagger board forward like the da tuo. 

As of 1935 and the introduction of the Suicide Class, centreboard dinghies (far bigger, heftier...and slower than today's) began to proliferate. That said, the real expansion had to wait until the end of WW2, the reoccupation of HK by the Brits, and the reach-me-down re-start of sailing thanks to gifts of drop-keel small craft, RNSA (Royal Naval Sailing Association 14' class (on which this aged writer cut some of his early sailing teeth in the late '50s and early '60s)) from the Royal Navy. Then subsequently beginning in the late '40s, came Uffa Fox's Redwing and in the '50s, the L Class, designed originally in Yokohama by American expat John Laffin. Both boats were either traditional clinker built planked craft (Redwing) or full frame carvel build (L) and had steel drop keels, which were fairly normal in those years, plywood being something pretty new.

It wasn't really until the '60s that the modern sort of dinghy racing took off in HK as in Europe and the USA, partly because of increasing affluence, but largely because of the advent of good quality, inexpensive and widely available plywood thanks to the upscaling of its design and manufacture as part of WW2, and the plethora of new, DIY designs in plywood available from the many designers who had moved into the dinghy design field (e.g. Uffa Fox, Ian Proctor, Jack Holt, Barry Bucknall, Peter Milne, Sydney Cheverton...and that's just a sample of the Brits). 

That brings us pretty much up to where we started, the history between say 1970 and today largely being about varying proportions of the fleet in each category and the radical changes wrought by the introduction of GRP and aluminium spars and, more recently, more exotic materials like carbon fibre.

Hope that more or less answered the question.

Best,

StephenD