PHRF of New England will handicap just about any self-righting monohull yacht that can pass ORC Special Regulation Category 4 requirements. The corollary to this is that you can do almost anything to your boat. We will estimate it's impact on speed and adjust the handicap accordingly.
The key to accurate performance evaluation is knowing the configuration of the boat. Unless told otherwise, we handicap the boat as it comes from the factory. This means a complete interior with berths, cushions, doors, tables, etc. If for some reason you do not want to sail in this configuration, this fact must be noted on the handicap application. The PHRF of New England Handicapping Committee will adjust the base handicap of a "stock boat" if the modifications or changes, in it's judgment, warrant it.
It is not the owner's responsibility to assess the speed significance of a change, although reason must apply. If you move winches or add an inboard genoa track, these are considered tuning and no handicap adjustment would be applied. If, however, you replaced your rig with one made of carbon fiber, or put on a new keel two feet deeper than before, or any other of a myriad of speed enhancing modifications a handicap adjustment is expected. Minor keel and rudder faring is expected. If you completely change the foil section of the blades, this must be reported.
If the initial handicap for your boat is based on a measurement rule such as IOR or IMS, you must sail the boat in the condition the boat was measured. If you changed anything that would require the boat to be remeasured, that change would obviously have to be reported on your PHRF application. This includes the changing of internal ballast.
Over the years, the Handicapping Committee has uncovered many violations of the above philosophy. When the owners were queried why the didn't report the changes we have received all kinds of excuses such as "there was no place on the form for that measurement", "I asked the race committee and my competitors and they didn't mind", or simply "I forgot". It is truly amazing how so many apparently successful people can have such poor memories. In the end it is not fair to your competitors. It is cheating.
Most of the above mentioned cases were known to competitors. Yet they didn't protest the offending yacht. The Handicapping Committee cannot be everywhere and know everything. It is also not their job to police the fleet. If you suspect that someone has an unreported modification, don't bitch about the lousy system for not bringing the culprit to justice. Do something about it. Protest. Send a message that cheaters can't get away with it.
When you sign your handicap application, you agree that you understand that it is your responsibility to notify the handicapper of changes that would alter the boat from a standard boat. This means that you must report the changes every year as the certificate is a record of the configuration of the boat. If you are found in serious violation of the fine print you can be suspended from sailing in PHRF races or, in more extreme cases, can be banned from the sport of sailboat racing.