Offhand, I expect he's pretty close to being right on the money...
So, what does that work out to in real terms?
Let's start with someone who weighs in at 180 pounds and (giving the benefit of the doubt) is a lean and mean machine. That gives us a displacement number of 9000 pounds... A nice round number.
By today's standards, a 9000-pound displacement boat is not very big and you'd be hard pressed to find one over thirty feet in length. Just for a sense of what some popular VolksCruiserish boats displace...
- CAL 34... 9500 pounds
- CAL 28... 6000 pounds
- Pearson Vanguard... 10300 pounds
- Pearson Triton... 6930 pounds
- Columbia 34... 10500 pounds
- Coronado 32... 11800 pounds
Where Fitzgerald's numbers work is that they give you a pretty good idea of what's within your physical abilities without resorting to some sort of problem prone auxiliary assistance like powered winches and suchlike.
Maybe it's just me, but I'd feel nervous about sailing a boat where such needful acts like sail handling or picking up an anchor is beyond my physical ability.
Anyway, it's something to think about.