My wife and I have a couple of large (Samsonite) suitcases and wish to catch the speedboat from the mainland (pier in Rayong district) to the shoreline outside our hotel on Koh Samet.

I understand that obviously we have to walk from the boat (on the shoreline) in knee deep water so I'll obviously be wearing sandals, flip flop thongs or similar footwear however...,.

with the large suitcases  (20kg each)..  do the boat crew say "you're on your own" or do they help you carry them to shore.  I guess a healthy tip would be in order.

Has anybody caught these speedboats from the pier to Koh Samet (as opposed to the ferry)?    I've watched YouTube vids but travellers seem to be with just hand luggage or backpack.

My other option would be to leave 1 suitcase at LOCKBOX in BKK...  are THEY user friendly to organise?

Probably too late as an answer but in case it helps anyone else. Generally the speed boat people are helpful and will help you get in and out with your bags (I was there a couple of weeks ago). But they are not allowed to drive you directly to your beach anymore; your speedboat can only drop you at the main pier and from there you have to take a songtaew. 30 baht each if you don't mind waiting for it to fill up with passengers or 200 baht if you just want to take the whole thing for yourself. (That was the price to just near Ao Phai anyway).