sure. Dinghies have no keels. Most catamarans have no keels per se.

You may have a problem in the terminology. See, the ‘keel’ is a ballast in the boat, usually some heavy metal. Also, big boats have a central ‘keel’ that’s actually their ‘spine’, that holds them together, the deepest part of the hull.

A sailboat usually needs a ballast, a keel, to counter the forces of wind on the sails. If the boat has some other ways to do this, it doesnt need a keel. Dinghies are small boats, where the counterforce is provided by the weight of the crew.

For example, on this 470, one crew is on a trapeze, to place his weight completly out of the boat for maximum counterforce. However, this boat has a centerboard, for lateral resistance.

Whereas this Hobiecat has no keel, and no centerboard either. The lateral resistance is provided by the leeward body in the water.

now, keelboats have a centerboard, and a keel attached to it. Classic boats have a so-called long keel, with a big lateral area, and the ballast in the lower part of it. It usually has the rudder attached too:

moder performance boats have a long narrow spade and a very visible bulbous keel on the end for maximum force. Such boats have separate, blade rudders, in this case, two.

now, very high performance boats have a swing keel. To maximize the counterforce provided, they can swing the keel windward with some sort of mechanical or hydraulics force.

interestingly, since the keel swinged to the side does not provide lateral resistance anymore, such boats often have daggerboards, similar to centerboards in small boats.

If you are going downwind, you actually need no (or much less) lateral resistance, so small boats actually lift their centerboards.

Classic boats usually went downwind with their old-fashioned full rigging sails. But they still had a ballast in the lowest area of the boat:

just as this aircraft carrier has water ballasts in the underwater areas for trim and stability.

Good evening

I am 62 retired farmer from the North East of Scotland. I am very practical, not very clever but I can generally figure out how to fix most things.
Four years ago I had no sailing experience other than sailing Hoby cats on holiday. I have a friend with a 1976 O’Day 30. He invited me out on a sailing weekend and that was me hooked. Next stop one week day skipper course. Still very basic but basically gave me an introduction to safety at sea and navigation.
Three years ago I bought my self a sail boat and decided to teach myself how to sail

Susannah 36ft Dehler 36CWS in Fair Isle. April 2019

Since buying Susannah I have traveled over 4000 miles. Including a trip to the Faroes, West coast Scotland round Cape Wrath and extensive cruising in the outer Hebrides and Orkney. I nearly always sail on my own. Susannah I well kitted out with a decent autohelm, chart plotters, AIS and is relatively easy to sail single handed.
In my experience the only way to do it is just get on with it. You can ask 20 experienced sailors for an opinion about something to do with sailing and each one will give you a different answer. Ench opinion is probably correct. Sailing is like any sport, practice and experience.
The sailing part is the easiest. The challenges are, navigation, tides, currents, maintenance, weather, safety, crew safety, rules of the road to name a few.

Susannah in Torshavn, Faroes. May 2019

So to answer your question. No it’s not unrealistic.

Thank you for reading