expilot

The only way to know what your boat needs for Potter is to have her offered up to establish exactly what she needs, From the photograph, my concern would be with both the side screens (unless they either fold or are removable) and then the pulpit/side rails which will be your next highest point at the bridge.

When the pilots' office gauge reads 6' 11" the actual bridge clearance is 7' 0" and is the only accurate gauge for the bridge clearance height. There are at least four other bridge gauges actually on the river and not one of them measures the height consistent with each other, let alone the 'official' gauge. As a footnote, I might add that you may be surprised to hear that very many people read the gauge as illustrated in Howard's photograph as 7' 1"!

I started my ten year piloting career at Potter bridge at Whitsun, 1988. Each season, Easter to November, we piloted anywhere between 10,000 and 15,000 boat passages between us. Prior to that year, Hoseasons employed two pilots and Blakes two also. In 1988 the pilot service was combined - joint Blakes/Hoseasons. I suspect the pilotage figure is nearer 1000 a year now. Yes, the boats are bigger, yes they are wider at their tallest point, but, more importantly, in the thirty odd years I have occupied a riverside bungalow above the bridge at Potter, water levels have most certainly risen by at least an average of four inches. Back in the day, Bounty/Solar 37s, Hampton Safaris, Connoisseurs, Broom Skippers, Bounty 27s, Seamaster 27s and Elysian 27s were almost certain to get through the bridge - often even on high tide. Occasionally we even put through boats needing all of 7' 3" air draft. Water levels have risen to such an extent that I have lifted thirty-two Thurne bungalows, at the last count, to clear them of the high Winter tide levels. Dredging? I don't know if it would help.

The tidal range at Potter is 4" High to Low at every tide cycle irrespective of neaps or springs, BUT, after a full moon the High tide gets higher, the Low tide will remain stubbornly 4" lower than the higher High tide level. The tidal range is not increased. In theory, of course, the range should increase. It does at sea. Some people always assume that because we haven't had significant rainfall, the tides will be lower. The tides AND the rainfall are determined by air pressure. Low pressure means rain. High pressure brings sustained dry spells. No rain DOES, indeed, mean lower tides, but the lower tides are caused by the High pressure. The above observations are, of course, based on almost forty years of living on the river and ten piloting at Potter. They are empirical rather than being based on theory. The largest hire boat through Potter bridge over the last few days has needed 6' 7" air draft. Three or four such have been successfully piloted through.

Watching your progress with Broadland Grebe has made my heart pump faster and harder. I have so much admiration for your courage and determination to do the job properly. These beautiful old woodies deserve to be restored. Grebe is obviously in safe hands. Broadland Swift has been out of the water for the past twelve months having her stern bottom replaced in glued and nailed strip iroko - as originally built. The hull had rotted from the inside (rainwater via the stern companionway). The hope is that, as soon as the new stainless stern gear is ready to be fitted, she will be relaunched soon and then converted to electric propulsion. The tonne and a half Lister Freedom 4 and Blackstone gearbox have been removed - the silencer alone was heavier than I could carry comfortably! You know that, when you next come up North, you're welcome to moor above the bridge at Potter. I shall drool all over handiwork! Very, very well done.