Alderney is often used as a jumping off point for those coming down from the South Coast and going on to Guernsey, Jersey, or Brittany. It's also a favourite destination for French boats at the weekend coming from Cherbourg or other fairly local ports.
It's a little too far perhaps for a weekend trip from England, being a full day's sail from Poole or the Needles. It also lacks the 'big town' amenities of Cherbourg or Peter Port, and in addition, you are confined to a swinging mooring.
The island does have something of an old world charm, however, and is worth exploring - although you have to be fairly fit to make it up to the top! It is a place where to some extent you have be self sufficient, but that, in a sense, is one of its attractions. No big marinas, just a mooring buoy around which can swing in peace [providing you can find one in the first place, and providing the harbourmaster or water taxi isn't zooming past].
A note of caution: the harbour is very exposed to the north east, and the moorings become very uncomfortable with the wind in this direction. It is advisable to check the weather forecast regularly.
From the Needles:
Nice and straightforward, providing you make very careful allowance for the tides! The course to steer is around 200o. Do NOT end up downtide of Alderney, or you could be in for a long wait if you do. Normally you would leave the Solent on an ebbing tide and allow twelve hours for the crossing, which means you arrive on the ebb. This means aiming off towards Cap de la Hague, which, given a west or southwest wind allows you to sail a little freer. Similar arguments apply if leaving from Poole, although the passage time might be a little longer. Given the prevailing souwesterlies, it is often a beat all the way.
Crossing from Portland/Weymouth is also a useful option. Distancewise, there is not a great deal to choose between Portland and Weymouth.
Leave around 3 hours before high water Dover and head for Omonville. There is a counter current that will help you if you keep relatively close inshore. Beware of rough water near Basse Brefort bouy. Aim to arrive at Cap de la Hague at high water, and try not to get swept down the Race. It is always lumpy by Cap de la Hague.
In reasonable visibility you can see the island clearly as you come round the corner. You can also make it in one tide from St Vaast if conditions are right, but you will have to make good speed. You need to leave as the lock opens, and keep inshore up to Barfleur to take advantage of the inshore eddy.
Leave Peter Port with the first of the northgoing tide and head up the Little Russell. Alderney should be come visible when you are a few miles away from Guernsey. The lighthouse on the Casquets can also be seen, providing visibility is reasonable.
You can come west side round the island through the Swinge, but time it carefully with the tide: you can run into rough water. It is more comfortable arriving at the top of the Race at High Water and turning west to aim for Braye. Don't cut corners round the island.
There are good leading lines by day and excellent leading lights by night. They are on a bearing of 215o.
As mentioned below, there is a submerged extension to the breakwater which stretches some way out, and so if you are approaching from the West you need to stay well out before turning to enter. Ideally, you should be on the leading line about half a mile before the harbour entrance.
If you are on the leading line you should be well clear of the submerged part of the breakwater - nine times out of ten you can get over it, but depths are not obvious and boats have come to grief on it. It is often noticeable by the overfalls over it. If coming from the west, head past until the harbour is well open. Preferably find the leading line before you turn in. Beware of strong tidal cross currents.
Mooring buoys only. They have been provided with decent ropes attached to them, so now you no longer need to provide your own line. Mooring fees are £15 per day and £5 per day for anchorage.
You can anchor, but you would need a long chain, and there are plenty of bits and pieces on the sea bed to foul your anchor. The best moorings are closest to the old harbour, but then you do suffer from the wash of the water taxi.
The harbour is uncomfortable verging on untenable in winds from north through east. If strong northeasterlies are forecast, head off out, or be prepared to roll heavily.
To get ashore you need a dinghy or use the water taxi (expensive if you have a large crew). It can be a long row.
The showers, toilets, launderette, telephones, chandlers and a skip for rubbish are all close to the dinghy pontoon. The launderette is in the same building as the showers, and uses £1 coins. There is a fish and chip shop nearby; and also a reasonable grocer's shop for basics such as bread and milk, all close to the landing pontoon.
The town is a long walk up the hill.
You can get fuel and water from the inner harbour at high water. Be careful, since you tie to the wall, and the tide rises and falls very rapidly. Mainbrayce run quite a well stocked chandlery and are also marine engineers.
Alderney is not a place for great excitement. You are on a bouy in a large bay [see the pictures below], and, once ashore, there is little in the way of entertainment. The island does have a charm of its own, however, and even a walk along the breakwater gives you views across the Swinge and to the Channel shipping lanes.
Useful links: http://www.visitalderney.com/visit/sailing/information/ and http://www.alderney.gov.gg/article/4155/Harbour