You could take a boat, but the travel time for that is often more than 【what most people can reasonably fit into their trip】.
【】里是从句，正常语序是most people can reasonably fit what into their trip，what按照上文指代的是travel time。

句子斯文，礼貌，弯弯绕。
他其实说，大家不能接受这种慢船，太浪费功夫了。