Very few! That’s our whole philosophy of “No Surprise Extras”. In general, if it’s on the boat – it’s included. If it’s ashore – it’s not.
In the Med, our trips are mostly skipper-only – so we provide the provisions for breakfasts & lunches, and everyone pitches in to help. Dinners are always ashore in little local tavernas. A cook/first mate is sometimes available; this is at an extra cost.
In Thailand & the Philippines – we have amazing cooks onboard; they take care of all breakfasts & lunches. Dinners are usually half the time on the boat, half the time ashore. All meals on the boat can also be arranged.
The only other spending money you’ll need is for land activities; eg in the Med, you might rent scooters, jeeps, do some of the guided historic tours, etc. In Thailand, how could anyone resist those massages-on-the-beach! These costs are still all very reasonable, however.
Of course, if you decide to go hit the town and get into expensive cocktails, this will clock up a few extra $$s. Though all things are relative: you probably couldn’t spend as much on a night on the town as you would at home, even if you tried!
Note: There are a few dangerously enticing shopping spots; eg, Turkish bazaars, Thai markets… even those who claim to “hate shopping” have been known to sneak back to the boat with armfuls of goodies. You have been warned.