If you’ve been looking into cruises, chances are you’ve come across some deals that sound almost too good to be true. Maybe you’ve even been lucky enough to score a cruise offered for as little as $100 by leveraging hotel elite status matches.

But once you put down your deposit and start looking into all the extras, you’ll find that what you actually end up paying for your cruise vacation can easily be many multiples of the advertised rate that initially lured you — especially once you factor in flights and hotels.

Cruise companies, like airlines, make a lot of their money off ancillary fees. But there are ways for you to avoid some of these pesky surprises. Here’s how to save money on a cruise.

1. Cruise excursions

Potential added cost: $600-$1,200 (3 full-day excursions for 2 people at $100-$200 each, per person).

Frugal alternative: DIY at a level you’re comfortable with.

From the moment you book your cruise to the days you’re sailing, you’ll hear and see a lot of pitches for cruise excursions, which can be a tempting way to fill your hours in port while leaving every small detail to the cruise line.

But you’ll pay a huge premium for that convenience.

Assuming you’re open to some (extra) adventure, many excursions can easily be replicated for a fraction of the cost.

For example, on a recent Mexican cruise, a friend and I walked about 20 minutes from the cruise port along a well-maintained sidewalk to undertake a mountain hike for free that had been offered as an excursion for $60 per person. We figured we were already hiking anyway, so why not tack on an extra mile or so? A local bus would have done the trick, too.

Not quite so adventurous? Look into taking taxis, which are generally easy to find at any cruise port. Even that would have cut the price from $60 per person to roughly $5-$10 per person.

Here are a few other overinflated offenders you can easily replicate on your own or by booking ahead of time with well-rated local vendors:

Bike or walking tours.

Open-air bus tours.

Transport and entry to a beach club.

Boat excursions.

Cooking classes.

Pretty much anything offered in port can be put together independently. And local vendors are very much aware of ship times, so don’t worry about getting left behind. Their reputations depend on getting you back safely.