I say to my wife, 'I wish I had a Rao's to go to. I wish I had a Rao's to go hang out in, to go sit at the bar and meet wonderful people, and then sit down and have a wonderful meal," he says. I can see why. Whether the rotational RAO data are in degrees (or radians) of rotation per metre (or foot) of wave amplitude, or in degrees (radians) per degree (radian) of wave slope or wave steepness. As well as displacement RAOs, which directly specify the motion of a vessel in waves, OrcaFlex can apply wave load RAOs, which represent instead the load (force and moment) on a vessel due to waves. In this case, the amplitude represents the magnitude of the force (in the surge, sway or heave direction) or moment (in the roll, pitch or yaw direction); the meaning of the phase remains unchanged. Example: Damping (Hydrodynamic) forces due to the oscillations creating outgoing waves which carry energy away from the ship. The vessel has 6 degrees of freedom: 3 translations (surge, sway, heave) and 3 rotations (roll, pitch, yaw), so the RAO data consist of 6 amplitude and phase pairs for each wave period and direction. The RAO amplitude and phase vary for different types of vessel, and for a given vessel type they vary with draught, wave direction, forward speed and wave period / frequency. It is important to obtain accurate values for the RAO amplitude and phase if the dynamics of the system are to be correctly modelled.

Just think about what happened while you were here," he tells me, putting his hand on my forearm for emphasis. "You met my tailor. You met Tony Tantillo. You met Tony Abbot." (I met a trio of Tonys, if you include Tony the bartender.) "You met all these people. You met the congressman. You're seeing Rao's." And because it's so bright, which Frank says is because "it adds to the energy of the room," I really am seeing everything.

I am married 46 years," he says. "Same woman. She's great. I love my wife. 46 years. Does she come here? No. I don't want her here. When I come here, I work. What am I going to do? Sit with her at the bar? I have people I have to talk to, things I have to do." She doesn't eat shellfish or meat," I say, louder this time. "But I eat everything and I want to try what you're known for."

The coordinate system used to define vessel motions and, in particular, which direction is positive. That is, whether surge is positive forward or aft, whether heave is positive up or down and whether pitch is positive bow up or bow down. No one gives them up," he says. "Every table has been booked every night for the past 38 years. There's weeklies, biweeklies, monthlies, and quarterlies, so in every three-month period, I see all my clients. And now I'm dealing with their children and grandchildren." How we doing guys? I'm Joe," our waiter says. He sits down at the table. "What we like to do is, we serve everything family-style. For appetizers we have seafood salad, roasted peppers, baked clams, fried calamari, mozzarella in carrozza (that's deep fried), fresh mozzarella and tomato. We could do a salad. I also have mussels in white wine sauce. Those are the appetizers." M + A ( ω ) ] x ¨ + B ( ω ) x ˙ + C x = F ( ω ) {\displaystyle {\big [}M+A(\omega ){\big ]}{\ddot {x}}+B(\omega ){\dot {x}}+Cx=F(\omega )} A surge RAO of 0.5 in a wave of height 4m (and hence wave amplitude 2m) means that the vessel surges to and fro -1m to +1m from its static position; a pitch RAO of 0.5° per metre in the same wave means that the vessel pitches from -1° to + 1°.

It's 10:20 p.m. We've been here since 7:45, but the hours have gone by in a flash and I have no desire to give up my bar stool and leave the center of all the action. Good guy. I like him. He's okay. I could sit with Peter King and say what I like and what I don't like. I'm a political junkie," Frank says. There's a letter from President George H.W. Bush on the wall. Frank doesn't discriminate. Different modelling and design criteria will affect the nature of the 'ideal' RAO curves (as plotted graphically) being sought for a particular ship: for example, an ocean cruise liner will have a considerable emphasis placed upon minimizing accelerations to ensure the comfort of the passengers, while the stability concerns for a naval warship will be concentrated upon making the ship an effective weapons platform. There are many different conventions for defining RAOs. There have been attempts at standardisation, but these have not been successful so there remain differences between the main computer programs and model basins: some establishments even use different conventions for reporting model and computed data. The only safe course is to obtain a complete description of the system used for the data in each case.