Mechanical propulsion is wonderful, but if you don't have it for some reason (no motor or dead motor) you will need to rely on other methods to work your boat through close quarters. Marinas are especially tricky to sail through. The fairways are not wide enough to short tack a full keel yacht, and any mistake will lead to a very expensive collision.
Oars, sculling or sweeping, work as a wonderful solution to the call for mechanical propulsion, but it does have its limitations. Rowing a boat is the equivalent of using a tiny outboard on the back of a large barge. Yes, it will move but it will be very slow. Other forces such as wind and current will have a greater influence on your vessel than you could ever hope to have with your oar. This is why I reserve oar power for windless days in still water when I can maintain complete control over the boat via a single oar.
When the wind pipes up though, the oars are stowed and the warp lines are deployed! Warp lines offer "nearly" complete control over the craft while moving about in close quarters.
Warp lines are long ropes that extend from the boat to a fixed object in the distance. Marinas offer plenty of these fixed objects, be it pilings or mooring cleats, they are plentiful and in close proximity!
I like to use 300 foot warp lines (I carry two of them) because they are long enough to reach a distant cleat, but not so long as to be un-manageable. If I find that my 300' warp line is not long enough, I can tie other lines to it with sheet bends to extend its range.
To use a warp line, simply tie one end to a cleat on your yacht and keep the rest of the coil in the dinghy, ready to pay out as you go. As you row towards your fixed point in the direction you wish to go, the warp line will pay out to your boat with minimal drag on your rowing craft. If you left the coil on the deck of the boat and payed it out to the dinghy, you would find it incredibly difficult to row and drag all that line through the water; the resistance would be intolerable. When you reach your distant fixed object, simply tie the line off to it and return to your boat.
Standing on your deck, you may begin pulling yourself towards this fixed object. Your boat will move straight and steady towards this fixed point! This sounds like a wonderful solution to get out of a marina, but as always it has its drawbacks.
Strong winds
Strong currents
Lack of straight line path
Strong winds and strong currents can make it very difficult to pull a heavy yacht by hand. Luckily, most windlasses have a section for rope which can be used to crank in the warp line (by un-clutching the chain gypsy). If your windlass does not have this feature, you can also use the sheet winches in the cockpit, just make sure you have a fairlead near the bow to keep the boat pointing forward instead of turning around and leading by the winch.
If you are trying to move side to the wind, you must be careful that the boat will not swing into other moored vessels as you journey towards your fixed attachment point destination. If you are moving beam to the winds, a beam warp line might be necessary to control lateral swing. These lines will be tightened and loosened as you progress towards your destination.
Similar to these concerns of traveling beam to the wind or current, traveling through close quarters without straight line access to your destination can create a situation where multiple warp lines are needed. When you tie up in your slip, you don't just use one line, you use many! All of these lines work in harmony to keep the boat in position and under control. The same holds true with warp lines. The use of various warp lines in multiple directions will ensure that control over the vessel can be maintained as you move about.
As you may be thinking, each of these lines adds complexity and the need for additional crew to deploy and control all of these lines. It also takes time to run the lines out and bring them back and you need to be carrying all of these long lines on board, hence why engines gained such rapid popularity!
When I warp out of a marina, I like to keep it to one line. A second line adds a great amount of complexity and I can't always manage both at the same time. By planning ahead, single warp line departures can be successfully executed without much fuss. Next time you need to get out of a tight slip, consider using warp lines instead of praying that your propwalk will help you this time.