[LW] [LW11] Time to burn in Lighthouse 3 sailing tools

[jfxk]

I've read and re-read the lighthouse 3 manual and need help understanding what "time to burn" means under each option: 1) using polars, and 2) fixed angles.

Is it based on the speed (optimum or actual) and distance to the start line when sailing at the optimum angle (from the polar or fixed angle) or based on the speed (optimum or actual) and distance to the line based upon the direction the boat is pointing at moment the "time to burn" is read by the user?

Thanks
John

[Louise - Raymarine - Moderator]

Dear jfxk,

Thank you for your post.

Time to Burn uses predicted SOG data with the current conditions and laylines to work out how long it will take you to go along them to the start line. The start line being your closest intersect point.

When using polars - it is calculated using the theoretical speed over the ground data contained within the polar information.

When using fixed angles - it is calculated using the manual speed over the ground data you enter.

Many Thanks
Louise

[jfxk]

Thank you Louise - one of the options in Lighthouse 3 is to use actual speed. In that case would it calculate the time to burn based on actual speed over ground or would it be speed through the water changing as the boat speed changes? Thanks

John

[Louise - Raymarine - Moderator]

Dear jfxk,

If you have fixed angles or nothing set, you can opt for manual speed input or use your speed through the water data. It does not use speed over the ground.

Many Thanks
Louise

[jfxk]

Hi Louise and thanks for the clear explanation of how this works. I have a strong suggestion that Raymarine consider providing a user option of using "speed over ground" "SOG" in this situation in a future release. It is not uncommon for race start lines to be located in areas where there is a significant current effect on timing the start, particularly when wind is light. That current can push either towards or away from the line and have a huge effect on time to burn. Also STW transducers are know to foul easily. In the crucial 30 seconds or so before the start the best tool to know whether to speed up or slow down is time to burn based on SOG. We have used this on smart phone software that is far less accurate than a tool like the AXIOM with great results. There are also dedicated hand held GPS products out there that use SOG that are selling well. It would give Raymarine a strong competitive edge in the sailboat racing community to provide this option. Thanks

John

[Louise - Raymarine - Moderator]

Dear jfxk,

Thank you for the response.

I have submitted your suggestion to the product manager who can review this as a future feature.

Many Thanks
Louise