1. on board the craft是没有问题的；
2. 这里on board = aboard，这里要方便理解的话，不妨看作一个phrasal
preposition；根据OED的说法，on board作介词，also as prep., short for on
board of，是on board of的缩写。楼上的链接给出了不少例证，我再来几个。
on board 1. 上船（或火车、公共汽车、飞机等）；在（船、火车、公共汽车、飞机
When everybody was on board, the ship sailed. 等所有的人都上了船，船启航
He has never been on board a ship before. 他从来没有乘过船。
on board 1. 在船上，在船[飞机]中 (on board the plane 在飞机上)；
PHRASE 短语在火车（或轮船、飞机）上 When you are on board a train, ship,
or aircraft, you are on it or in it.
【搭配模式】：PHR after v
They arrived at Gatwick airport on board a plane chartered by the Italian
PHRASE When you are on board a train, ship, or aircraft, you are on it or
in it. 在 (火车、轮船或飞机) 上
All 269 people on board the plane were killed.
- on board
1 on a ship or plane 在轮船上；在飞机上
A customs officer came on board the ship.
on board On board the ship were several trucks. 船上装载著数架卡车
6. on board
a. on a ship, plane, or spacecraft
在船上; 在飞机上; 在飞船上;
There are 12 children on board the ship.
We went on board the ship. 我们登上了轮船。
九、Kernerman Advanced English Dictionary
7 on board on a ship, plane or train: There were two hundred passengers on
board the plane. We went on board at 8 o’clock.
十、The American Heritage Dictionary of the English Language, 5th Edition
2. Ready to participate or be included; amenable:
The entire class was on board for the excursion to the park.
十一、Shorter Oxford English Dictionary, 6th Edition
on board = aboard adverb & preposition.
1. : aboard
2. : in support of a particular objective
needed to get more senators on board for the bill to pass
Webster's Unabridged 3
: in or into a working relationship
Merriam-Webster's Advanced Learner's Dictionary
1 : in or on a train, boat, etc. : ↑aboard
She got on board the train.
The ship's passengers are all on board.
Is all the equipment on board (the boat/train/bus/plane)?
2 : included among the group of people who support a particular goal,
They needed to get more senators on board for the bill to pass.
十三、Oxford English Dictionary
c. on board: on one side, close alongside (of a ship or shore); also as
prep., short for on board of. (See also 14.)