St Martin Question

Hi! I am hoping someone can help with our St Martin day. We will be on the island on a Saturday. Kayaking to Pinel Island and visiting Maho Beach are MUST's. I know it is possible to do both because my sister and I did just this a few years back. Does anyone have any tips and costs of transportation? We are planning to rent kayaks from Caribbean Paddling - haven't decided if we are using their transportation or not (depends on whether or not they will bring us back to the ship early enough to then taxi to Maho for an hour or so). From what I read it is about a 30 minute taxi ride to Caribbean Paddling location. Any thoughts on what this would cost? Then we would also need a taxi to go from there to Maho and then return to the ship. On average, how long does it take to go from Maho Beach to the cruise terminal? If I remember correctly, my sister and I kayaked to Pinel Island and stayed there until around 12:00-12:30 then headed over to Maho for an hour or two and arrived back at the cruise terminal with time to spare. Any tips??