A few notes on how I get my figures.
Most 33 year old boats that I see look good but are going to need major refurbishment before going anywhere serious. I put $60+k in this case. It's a guesstimate, based on what I'd expect a similar boat (48' fibreglass) in rock solid cruising condition to sell for ($140k + $20 refurbishment).
Now we have a boat valued at $160k. We could put that money
in the bank and get close to 5%. Loss of opportunity is going to be more than that so say 8%.
The next big cost is depreciation. Say 8%. I like to combine that with maintenance
commonly estimated at 10%. So depreciation and maintenance
is looking to be somewhere round 18%.
Now add in running costs - docking
etc. I'd be guessing these would run between $6k and $12k p.a. Say 5%.
Now I'm up to 31%. Seems outrageous. No budget
conscious owner would spend that so I factor in 6% of savings to end up with 25% or $40k p.a.
The point is that most of these expenses are hidden. It's not like we're pulling $800 out of our pocket each week. But at the end of our 3 or 5 year cruise
the total cost for our example is going to be $120+k to $200+k.
I use the "$+k" as the cost each year could have been invested but my actuarial skills fail at that point.