If you are feeling really adventurous, you can do what I did in 1998 when travelling through Africa with some friends. One of our number decided that the Seacat was 'a bit pricey'. We were backpacking University students and he was the type who revelled in spending as little as possible. I on the other hand liked nothing more than throwing money at the problem and travelling in comfort but I got outvoted.

We walked up to the quayside in Dar and after an hour of intense negotiation with several people, my friend found us spaces on a boat for about a tenth of the cost of the (really quite cheap anyway) Seacat. This should have been warning enough.

We boarded a boat that looked seaworthy (else I would have refused) but noticed that we were the only foreigners on a boat full of locals, some of whom looked a little hostile, the remainder were openly laughing. An ominous sign.

What followed was a tortuous six hour journey in rough seas where the boat rocked violently from one side to the other like a fairground ride so that your view swung quickly from the horizon to the deep blue sea. I remember shouting, vomiting, shouting some more and then resigning myself to a quick death at sea. Eventually the sea calmed as we reached Zanzibar at which point our Captain decided to play chicken with a large container ship. Somehow we reached Zanzibar intact.

We got the seacat back to Dar a few days later.