Looking for economical way to get to the Museum Park from my cruise ship.
Well, you could walk which is the most economical I'd guess. It's about 1 kilometer so definitely doable when in good shape (you have to cross the Erasmusbridge however - a bit of uphill and downhill).
Or use public transport. Public transport in The Netherlands is paid with a OV-Chipcard - you pay €7.50 but that is just for the card not for travel - but they do sell day tickets (rather pricy at € 13,50 and you can buy single tickets as well in a bus or tram for € 3.50 with a 2 hour validity). Nearest tram stop is at the Wilhelminaplein (walk from Cruise Terminal in the direction of the Erasmus bridge and I think you need to cross the main street there. Probably the staff at the Cruise Terminal can assist you if needed. They get plenty of tourists.
It might no be the most economical way, but I think the Watertaxi is a very good option. (especially if you value entertainment) These high-power boats can bring you from Hotel New York (close to the cruise terminal) to Leuvehaven (which is a 10 minute walk from the museumpark). You can just walk up to the stop at Hotel New York, and ask for a ride.
It'll cost you €4.50 per person.
It's lots of fun, and my visitors always mention it as one of the highlights of their visit to Rotterdam. It's also amazing at night, when all the skyscrapers are lit up.