With crowded markets and narrow, often bumpy streets, Zanzibar sounds like the last place you'd want to venture to if you have difficulties walking. Wheelchairs and sandy beaches just don't agree, and to cap it all, Zanzibar's island status provides more logistical problems, forcing you to ask if the getting there is actually worth it.
It is. A Zanzibar experience is unique, and with some preparation, patience, and the innate helpfulness of the local people, you will be surprised by just how possible it is.

Getting there and away
The ferries from Dar es Salaam are not an easy option. Boarding on Zanzibar is via a gangplank, which is steep at low tide and can be difficult even for able-bodied people with luggage. On board there are various decks with stairways between them and there are no facilities to make mobility easier.
A quicker more comfortable and more practical (albeit more expensive) option is to fly. The airport staff reportedly cope well with disabled passengers, although you will need to be manually lifted in and out of the small 13-seater planes which are used for many flights from Dar to Zanzibar.

Accommodation
Put simply, I know of no completely wheelchair-friendly accommodation on Zanzibar. Most buildings' entrances are at least one step up from street level, and cheaper hotels are often small. However, there are many establishments throughout the island that can be construed as accessible, depending on your abilities and your willingness to compromise. The more upmarket the hotel is, the greater the chance that the rooms and bathrooms will be spacious, and that conveniences like bedside telephones will be present.
Unless you are going to have the time and energy to look for accommodation on arrival, the best advice is to research your options in advance. Specialist tour operators will normally take time to listen to your needs, or if you prefer, many hotels can be found directly on the internet. If photos aren't available, the owners are easily contacted and can describe their facilities by email.

Restaurants
Many eateries are on the ground floor, with one or two steps at the entrance. The proprietors will want your custom, so if you fancy eating there, you can be sure they will quickly organise a couple of waiters to help you in.

Transport
Buses and dala dalas are cramped, with no facilities for wheelchairs, and getting off and on can be a hectic affair. Therefore, unless you can walk at least to some degree then taxi is going to be your only easy way of getting around. Drivers will be happy to assist with transfers, but are obviously not experienced in this skill so you must be assertive and explain clearly what help you need. Tour companies often use minibuses - higher than taxis - for spice-farm visits and other excursions. This means you may need help from two people to transfer. It is always advisable for people prone to skin damage to sit on their wheelchair cushion in the vehicle as it may be old, meaning the seating won't give as much support as it once did.

Health
Doctors will know about 'everyday' illnesses, but you must understand and be able to explain your own particular medical requirements. African hospitals are often basic, so if possible, take all necessary medication and equipment with you. It is advisable to pack this in your hand luggage during flights in case your main luggage gets lost.
Zanzibar is hot all year. If this is a problem for you, a plant-spray bottle is an ideal cooling aid.

Security
The usual advice applies to all travellers, but it is worthwhile remembering that, as a disabled person, you are more vulnerable. Stay aware of who is around you and where your bags are, especially during car transfers and similar. These activities often draw a crowd, and the confusion creates easy pickings for an opportunist thief.

Activities
Stone Town tours, spice-farm visits and many other excursions are certainly possible. Inform your guide or tour company in advance of what you can and cannot do and they will make an appropriate itinerary. For some visitors, many of the older buildings will prove impenetrable. For instance, there is a ramp up to the Palace Museum but then staircases inside with no lifts.
Beaches will always be naturally difficult for wheelchair users. I've still not heard of anyone on Zanzibar using a beach wheelchair (wheelchair with massive tyres to ride on soft sand), but I have no doubt this will come. Until then, we'll need to be content with sipping a cool drink in the shade with a good book. Is that so bad?