20 boards, 20 wood, 4 tar, 4 rope, and 1 linen.
Total weight is 125 (the tar is heavy) and total bulk is 29. Should be no problem for acrobats.
You can disassemble the ferry boat after every crossing, with no loss of materials, so you only need to carry one per person.
A kit for building a short OR long range ferry while out travelling is somewhat larger (still no problem for someone who has mastered 4 moves in acrobatics, unless you have a LOT of other stuff you want to carry):
short distance ferry: 20 boards, 20 wood, 4 tar, 4 rope, and 1 linen.
long distance ferry: 200 wood, 20 tar, 20 rope, 4 silk cloth, 50 pliable rotproof boards, 50 rigid rotproof boards
together: 20 boards, 200 wood, 20 tar, 20 rope, 1 linen, 4 silk cloth, 50 pliable rotproof boards, 50 rigid rotproof boards
plus with a long range ferry you'll want to take small construction site kits - disassembling an improved ferry yields the above materials, but the construction site is lost. about 10 kits makes a nice, round number, making your total kit:
10 canvas, 20 boards, 200 wood, 20 tar, 60 rope, 1 linen, 4 silk cloth, 50 pliable rotproof boards, 50 rigid rotproof boards
total bulk 415, total weight 795. As mentioned previously, this can be carried by anyone with 4 completed moves in acrobatics.
A long distance ferry is supposed to be able to cross a distance of about 500 feet / 32 coords.