Rocky Point in Port Moody is a good launch ramp, but the price is extremely high at near $ 50 per day to park the vehicle and trailer.
Cates Park in North Vancouver is also a good launch ramp and more reasonably priced at near $ 30 per day to park the vehicle and trailer, but has a limit of 4 nights.
MacDonald Beach ramp near the Vancouver airport is similar to Cates park in terms of pricing and maximum duration.
Steveston boat ramp is similar to the Ladner Ferry Boat Launch (it is just opposite on the Fraser River). It is not free, but reasonably priced (I believe it is less than $ 20 per day, but have not used it for several years).
If you are planning to stay for more than a few days, also consider to leave the vehicle and trailer in a storage lot (or private short term storage that can be found on Marketplace). You can then launch at Rocky Point, drive the vehicle to the storage place and taxi or Uber back to the boat. You are allowed to leave the boat tied to the dock at Rocky Point for 3 hours while you go park the vehicle and return to the boat.
