With tides of only about 2-3 feet, our worst one here is one of the inlets that can hit 8kts on a large tide. With a hull speed of 6.5kts, we just have to wait it out.
Trip Planning Software
- Thread starter LeslieTroyer
- Start date
On a separate note, reading the install of my new still in the box autopilot I learned I need a Raymarine MFD to program the new software upgrades to the EVO system... You have any knowledge of this?
I would inquire of RM as to what the upgrades are and see if you need them...you can get the info through their forums. Every time I've updated, it blows away the lookup tables and I have to go out do circles again. But, mine is just before EVO..
I would inquire of RM as to what the upgrades are and see if you need them...you can get the info through their forums. Every time I've updated, it blows away the lookup tables and I have to go out do circles again. But, mine is just before EVO..
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,137
I have heard that cautionary tale by unhappy owners. Poor software management. Even though by today's standards these systems are fairly old school (electronically) you would think they could set routines to capture and reintegrate existing data. It is not like they are creating a new file format. And even then they could design translation apps to handle the exchange. Me thinks they are not getting the best apple in the basket to do this work. It is certainly not an elegant solution to scrub the data with each "improvement/repair" of software.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,137
On another thought, I was reviewing the process of study by Jackdaw to get his new certification. In doing so there was heavy navigational knowledge required to be demonstrated. Specifically the area of CTS route&execute planning when dealing with crossing a body of water experiencing tidal currents.
I understood the idea of crossing a body of water that has tidal currents swinging in both directions across a "rhumb line", how the fastest and shortest execution of the track is to maintain a constant compass heading. The current will push you first one way (moving you off a straight line course) but will push you in the opposite direction when switched and in the end you will move over the ground like a swing back and forth, but will travel in a straight and shortest line on the water.
Where I have a challenge is how do those forces work when the currents are constant in a singular direction across a rhumb line. In flight one crabs into the force (usually the wind) to fly a straight course over the ground. In reading the theories it sounded like that was not the best course of action for a boat. Can someone please explain how on water it is different than in the sky. I think that if the current is constant then you need to follow a compass heading that compensates for the force of the current. This heading would not be in the direction of the end waypoint, but would be a specified number of degrees off the waypoint that compensates for the effect of the current during the passage. The boat would travel on the rhumb line over the ground.
Think you for your help.
I understood the idea of crossing a body of water that has tidal currents swinging in both directions across a "rhumb line", how the fastest and shortest execution of the track is to maintain a constant compass heading. The current will push you first one way (moving you off a straight line course) but will push you in the opposite direction when switched and in the end you will move over the ground like a swing back and forth, but will travel in a straight and shortest line on the water.
Where I have a challenge is how do those forces work when the currents are constant in a singular direction across a rhumb line. In flight one crabs into the force (usually the wind) to fly a straight course over the ground. In reading the theories it sounded like that was not the best course of action for a boat. Can someone please explain how on water it is different than in the sky. I think that if the current is constant then you need to follow a compass heading that compensates for the force of the current. This heading would not be in the direction of the end waypoint, but would be a specified number of degrees off the waypoint that compensates for the effect of the current during the passage. The boat would travel on the rhumb line over the ground.
Think you for your help.
@jssailem - I fly a compass course that cancels out (I hope) the effect of the winds aloft, just like sailing a compass course to make the rhumb line good over the ground. If the notion of "crabbing" is hanging you up (because the boat can't crab), then just disregard it, because the airplane doesn't know or care if it is "cocked" into the wind relative to the course made good (except of course when putting it back on the ground). The idea is the same in either case - a vessel moving through a fluid, experiencing multiple forces. I hope this helps.