While I have been on the Ryndam at least ten times I have not been in a "wheel chair accessible" stateroom even though I use a walker or wheel chair. According to the HAL brochure there are four outside stateroom at the front of the ship on the A deck(the lowest passenger deck). These are called triples have two lower beds that can be converted to one; a sofa that converts to a bed.
The location of these staterroms are convenient for elevators to the show lounge but a long distance from the main dining room and Lido restaurant elevators. On the lower promenade deck there are two staterooms with the same facilities as those on the A deck, both are outside, about mid ship.
I have no info on the latest in getting wheel chair passengers to be able to go on the tenders/. I will be on the Ryndam the week of April 7 and if you e-mail me at firstname.lastname@example.org
I can further advise you what I learned whilst aboard ship..
I suggest you call Katy Ludwig, Special Requiriements Advisor for HAL at 1-800-541-1576 or e-Mail at email@example.com
. You might ask her about showers. On the Ryndam the O/S staterooms have a shower/tub. The tub is so high that I have to use a stool that can be knocked down so as to fit in a suitcase that was made for me. The inside cabins have nice stall showers.
Trust I have been helpful.Incidentally HAL has a policy that they cannot guarantee you a courtesy wheel chair. They say they have a limited supply doled on the fist come first served basis so you might need to being your own. They also allege you can take their wheel chairs off the ship, which I never experienced in th past.